The drawing of the receiving portion of a bridge quadruplex circuit in Doc. 449 describes a patent model to be constructed at George Phelps’s Western Union shop. The design was to be included in Edison’s 9 July agreement with Prescott.¹ However, Edison did not include Prescott’s name when he finally executed and filed the covering patent application (Case 112) in December 1874.²

This circuit represents a partial solution to the major quadruplex problem—namely, how to prevent the neutral relay’s response to reversals of polarity. Although on short lines the “bug trap” (circuit iopq in the illustration below)³ adequately by-passed the neutral relay problem, on long lines distortion lengthened the gap between positive and negative signals, rendering the bug trap inadequate. Here Edison replaced the retracting spring on the neutral relay with magnet u operated by polarized relay t in the main circuit; when the current reversed, the magnet momentarily discharged and the neutral relay armature did not move. ⁴ The other novel feature of this plan is the variable rheostat/condenser arrangement b aaaa, which allowed the operators to balance the artificial line more easily than before. The small magnets on the ends of the neutralPage 230 relay magnet cores are a design Edison patented in April 1873.⁵ Connected in a local circuit with a variable resistance, they could work with or against the primary magnets to compensate for varying current strength on the main circuit.

[Newark, c. July 1, 1874]

Model

[Newark, c. July 1, 1874¹]

Model. A.²

Page 2321 2 3 4, 5 are Rheostats. G is a small galvanometer like a pocket compass with two or three turns of 23 wire wound around it. X is a double spiral relay with the local point at the baek F is a magnet adjusted up to a fixed armature wound with fine wire. E is another magnet adjusted up to a fixed armature, but wound with two coils one of fine & one of very fine The latter is the smallest & connects to Rheostat .1.

X is a double relay. Each spool is wound with two Coils n & m are 23 wire the balance fine wire 5 is a Rheostat B a battery all connected in circuit with the coils m & .n.

New York, July 9, 1874^a

This memorandum of an agreement made the ninth day of July, 1874, by and been¹ Thomas A. Edison and George B. Prescott, witnesseth:

Whereas the said Edison and Prescott are the joint inventors² of certain improvements in telegraphic apparatus described as magnetic duplex apparatus, being the invention and improvements more particularly described hereafter, for which invention they are about to apply for letters-patent of the United States, to be issued to them jointly. ³

And whereas it is desired by both parties to enter into certain engagements with each other as to their respective interests in such patent, and in the use and benefit thereof.

Now, in consideration of one dollar to each of said parties by the other paid before the sealing and delivery hereof, and the receipt of which is hereby by each of them acknowledged,Page 233 it is covenanted and agreed by each of said parties with the other as follows:

1st. That the improvements and invention of which they are the joint inventors and in respect to which this agreement is made are all those inventions for making multiple transmission of magnetic signals for use in telegraphy which are described in twelve several specifications, now in the hands of George M. Phelps, for the purpose of making models of the machinery whereby such invention can be operated,⁴ and being all the inventions of said parties, whereby, at the same time and on the same wire, one message may be sent in one direction and one message in the opposite direction, or two messages at once in the same direction, or at the same time and on the same wire two messages may be sent in one direction and two messages in the opposite direction.

2d. That both of them shall have an equal, undivided interest in all future improvements of either of said inventions which may be made by either of them, and that, if it be necessary in order to secure such interests to either, the other shall make an assignment and transfer of such interest to him in due form sufficient to vest such interest in him, and to entitle it to be recorded in the United States Patent Office.

3d. That both of the parties shall have an equal undivided interest and be joint grantees of all letters-patent of the United States or any foreign countries which may be granted for all or any of said inventions, or of any future improvements thereof, and of all extensions and reissues of any such letters-patent.

4th. That whereas Edison has heretofore expended $1,125 for models and patent fees, the benefit of which he contributes to the common interest, and waives reimbursement of that sum, or any part of it, Prescott hereby agrees to pay solely and without contribution from. Edison all the future expense and cost of specification, drawings, models, Patent-Office fees, and patent solicitors’ and agents’ fees, and all other charges incident to the procuring of letters-patent for any of said inventions.

5th. That neither of said parties will sell, assign, or otherwise dispose of the whole or any part of his interest in said inventions or letters-patent therefor, or any of them, without the written consent thereto first obtained of the other party.⁵

6th. That neither of said parties will himself manufacture, use, or sell, nor grant licenses, or the right in any way to any other party to manufacture, use, or sell any of the said inventions, Page 234or any improvements thereof, or any machine embodying or article containing any of said inventions or improvements, or protected by any of said letters-patent, without the written consent first obtained of the other party.

7th. No sale of any of the said inventions and no license or right to make or use the same in any way shall be made or given except at a price to which both parties agree, and all net profits shall be equally divided between the parties hereto.

8th. The covenants and provisos of this agreement binding either of the parties hereto shall also bind his executors, administrators, and assigns.

In witness whereof the said parties have hereunto set their hands and seals the day and year first above written.

Thomas A. Edison, [l.s.] George B. Prescott. [l.s.] Sealed and delivered in presence of—R. H. Rochester. ⁶

[New York,] Migdnight July 9th/74

My dear Edison

I returned this P.M.¹ Have not seen Reiff but having learned what was going on have been all this Evening investigating & therefore beg of you to see me before you sign any more papers, take any money or go to any other place.² Come to 80 Broadway. I am in hopes that I can relieve you.³ At this moment adverse actions will cause a loss of 100 000$⁴ Truly

[Newark, July 13, 1874?¹]

Quadruplex instruments²

A and B are two magnets one inch in length, they may have a diameter the same as ordinary Morse relay spools, or Duplex relay spools. The resistance of each magnet is to be 200 ohms C is another magnet, one inch long, whose diameter may be small, resistance 50 ohms. The top armature is to be double Thus, The weight of the two not to exceed that of a single “half round” armature, which may be used with the bottom magnet.^a

The platina is to be “hard drawn.”³ The [-]local platina point is at the back X, with ivory in the point of the front screw The cores of A B and .C.. are to be ¼ of an inch in diameter and free as possible from permanent ma well annealed, if this is inconvenient the ordinary Morse size will answer nearly as well. The cores are to be slotted from end to end, witdth of slot about 1/32—depth, to the centre. Thus:—

A single layer of 23 wire is to be wound on each spool of A. and .B. after the fine wire has been wound on them These layers of wire must be well insulated from the fine wire

16 Binding posts The next diagram may make it clearer.Page 237

The dotted lines represent the 23 wire, use ordinary Phelps binding posts.

Four of these relays will be required.

FSix 6^b [-]sounders with spools one inch long altered as before thus:—

Theree polarized relays, same style as before to be obtained from Gold and Stock.⁴ Their tongues to be put in same as in Siemens Relay.⁵ The brass projection from the tongue to be a full 1/16 thick. The magnets to be inch and half long and wound with two sets of coils ⁶ Thus

if it is not convenient to put on rubber covers they may be dispensed with, connections thus

Page 238 Thus

The two returned relays are to have their tongues connecte[d]^c to the angle peice same as sSiemens, [-]the brass projection con from the tongue to be 1/16.—it spring[s]^c now = The resistance of A and .A. are to be about 150 ohms together^d and B .B. the same. The returned polarized Relays are to be rewound and made 150 ohms resistance, with a single layer of 23 wire wound over the fine wire and running to seperate binding posts.

Four such Rheostats as this.

A & B are two magnets of the same length as ordinary Morse wound with 200 ohms each, and so arranged that they adjust up to fixed armatures in a peice of brass C.

The Connections are made thus⁷

I should like to have this arranged as compact as possible, which might perhaps be done this wayPage 239

I have very little room for it on the table.

New York, July 15, 1874.¹

Mr. Thomas A. Edison, of Newark, N.J., has for some time past been engaged in perfecting a system of “Quadruplex Telegraphy,” or sending two sets of messages and receiving two sets at the same time over a single wire.² His apparatus being in order for experimental work, Messrs. Orton, Prescott, Hunter³ & Brown⁴ of the W.U. Teleg. Co., and Mr. Grant, ⁵ of the Montreal Teleg. Co., met in the electrician’s office on Wednesday, 8th inst, where they witnessed the successful working of the Quadruplex over a circuit of about two hundred miles in length, two wires having been looped to Philadelphia and back for the purpose.

Messrs. Bogart, Phillips,⁶ Boileau, Mixer, Cook, Fullum, Gramzow and Kennetly of the night force took seats at the instruments, and for an hour exchanged newspaper specials at a rapid rate, all the instruments working nicely and promptly.⁷ Some changes in the instruments have suggested themselves to Mr. Edison, ⁸ and as soon as these are made, in a few days, the experiment will be repeated on a longer circuit, it being proposed to use then a wire to Boston and back.⁹

Cairo Ritchie Co WWVa July 20/74

Messrs Edison & Murray

Your favor of 13 inst¹ just received and I send enclosed a rough sketch of the main feature in my improvement in the Electro Magnetic Engine

The figure is intended to represent a double contracting Electro Magnet, composed of 34 sections (17 in each leg of the magnet) besides the curved end pieces. When the magnet is extended the sections open leaving an interval of 1/18 of an inch This gives when closed a stroke of one inch. One layer of insulated copper wire is wound on these sections after the manner of electro magnets, but on each alternate section the wire is wound in the opposite direction. By a peculiar arrangement of the Breakpiece the current is sent in one direction and the magnet contracts with great force. Then the current is reversed on each alternate section and the magnet opens its length by the repelling force. The sections are of soft iron, hollow, slightly convex and concave where they touch when closed. The covering wire is not broken at the junction of the sections but is looped out so that the movement of 1/18 inch does not injure it. Another feature in this arrangement and which I have never observed in any other, is that when the machine is in operation, there is no surplus material or dead weight—every grain of copper wire or of soft iron being continually in active operation. I have here purposely avoided giving the details that you might better understand the main principle on which the machine operates, and I feel convinced that it will develop the full mechanical power of a given battery, and if the day should ever arrive when we could obtain electricity cheap enough, it would supersede steam as a motive power. At present however I see no reason why it could not be applied successfully to sewing machines and other machines where safety cleanliness &c would be more of an object Page 242 than cost of running. From your experience in electrical pursuits you should be able to form a good opinion of the merits of my plan, and if you think proper I will send a sketch of the machine in detail.² Yours respectfully

Indianapolis, July 24 1874^a

Friend “Al.”

I suppose that you will be able to call to remembrance the undersigned, as an old school fellow and playmate; and the times we used to have in the “cave” and the many wonderful things we planned but did not accomplish in our boyhood days. You, I am glad to see, have succeeded better since you have come to man’s estate, and have greatly improved upon old Ben’s chaining-lightning-performance May success still crown your efforts in future work. I have see short newspaper accounts of you late invention which enable one wire to carry four messages, but would be glad to see a fuller account. Your telegraph printing instrument I have not seen, but am likely to need something of the kind, as we intend to construct a telegraph line from our office to our yard, about one mile in length. Will you give me some particulars as to its workings &c and what a couple of them will cost us. We just started in business in February last and are doing very well for new beginners. I worked, previous to that time, 9 years in the Local office of the “Vandalia Line” at this point as Cashier, my oldest brother, George being the Agent.¹ Father and mother, my sister and two brothers, George & Frank (the latter married) are now living here. Father has charge of a church here, while my brothers are both still in the employ of the “Vandalia” Where are your folks now? I suppose some of them are still in Port Huron Let me hear from you as soon as convenient,Page 243 and let me know about the instruments Your Old Friend

[Newark,] Friday July 24th 1874

Geo. Harrington Dr

In July 1874 Edison created the model for his first patented transmitter-receiver for automatic telegraphy. ¹ Although the Automatic Telegraph Company had been using a combined instrument for some time, that instrument was operated by a hand-crank.² In his new design Edison used clockwork to rotate the transmitting and receiving rollers, which were placed on the same shaft and engaged by turning a switch.

In this design Edison made the transmitting roller larger than the receiving roller. Since the perforated paper would pass over the transmitter more rapidly than the chemical recording paper would pass over the receiver, the marks recorded at the receiving end would “be contracted proportionately”Page 246 and the instrument would use less chemical paper.³ To help electrically balance the line, Edison incorporated two switches (on the base of the machine, one on either side of the switch used to engage the rollers) that controlled variable resistances “under arrangements of circuits adapted to automatic telegraphy.”⁴

Edison had been working on a clockwork-driven transmitter-receiver since the end of March 1874.⁵ The impetus for it likely came from England, where tests were continuing on his automatic system. Letters from his agents in England often noted that the British Post Office engineers favored clockworks over hand-cranks. Edison criticized this enthusiasm for clockworks, although he stated that “if it is decided to use a clockwork,... I can furnish that article.” ⁶ The use of a clockwork in this transmitter-reciever may also have influenced (or perhaps been influenced by) his simultaneous work on a domestic telegraph receiver.⁷ Little evidence remains of Edison’s experiments with clockwork mechanisms for automatic telegraphy, ⁸ and the wooden patent model depicted below is the only known example of this design.

[Newark, c. July 24, 1874]

[Newark,] Aug. 3 1874^a

Experimental Philosophy

1.

See if H[ydrogen] evolved on the Lead will decrease its specific gravity Solution Caustic Potash.

1^b 12 cups of battery used Bunsen Cork raises slowly but is entirely due to mechanical means so much H collecting under the lead as to considerably lessen its weight. Acts slow.

〈Batchelor 20 hr different exp.〉^c

[Newark,] Aug 4 1874

Sulphide of Iron (FeS.)

Made this from bar Iron heated to a white heat & pressed against a bar of sulpher over a water bath into which it drops after combination with sulpher It is brittle & has a look slightly bronzed

[Newark,] April[August]¹ 5 74

〈Automatic and Emg〉^a

Qinine Sulph. HO. NChl Sod. Hyd Ammon.

Marks with tin pen on Hydrogen side.² Platina shows Edsons N[ew] F[orce] good on both. Tin on Hydrogen side shows well. The tin pen marks black but its not so very sensitive. Lead pen is most sensitive. N.E Shows splendid on this solution. Extra good I think on account of the lead being reduced & giving a mark I think this is necessary for that purpose that the lead [-] should be reduced to get sensitiveness, though platina shows it on short ckt it wont on 10 000 ohms & 6 cells Carbon while lead is fearful strong.

Aniline,³ Excess lime water, boiled for some time & then Page 250 filtered hot, Yellow solution. No marks but Lead shows extraordinary strength N.F. better than Qunine above. I find on trying Potash that it is as good probably morse sensitive but above appears to act sharpest and evenest, paper smoother. I added salt to last, but no marks obtained.

〈Edison Batchelor Adams⁴ Fox⁵ Charley⁶ 12〉^a

[Newark,] Aug 7th 1874 4. AM.

Pyrogallic Acid with salt & lead pen very sensitive on Hydrogen to pen. White paper & Blackish brown mark. Paper seems to be less sensitive as it is kept. All pens mark on Hydrogen side except silver. Page 251

Excess of Chi Na & Pyrogallic acid seems to be best² Quite sensitive even when small amt of Pyrogallic Ac is used

Chi Zinc kills it entirely

NH4 added to Salt solution no good Seems to be exceedingly sensitive to ‘new force’

Platinum marks on this but not so sensitive as lead which seems to be the best.^a

Platinum also gives on O[xygen] side³ a not very sensitive pale yellow mark^a

Changed the Instrument here Platinum to Iron-drum^b Pyrogallic Acid & Citric Acid no mark at all on any pen Pyrogallic Acid & Nitro Acid & Salt lead marks on small resistance not very good

Gallic Acids mark something like the same as Pyrogallic^a These last it seems may be due to the metallic drum on which they were tried as we changed it from Platina to Iron.

witness^c       Batchelor Edison

〈See Page 162⁴〉^d

[Newark,] Aug 7th 1874 4 AM

Repeated & recorded with Electromotograph (300) three hundred words per minute 10 000 ohms & 6 cells of Carbon with ordinary Ferrid paper & that rather dry. with Lead to a point.

Also tried winding several layers of paper round the drum but impractible. Put a piece of paper under lead & kept it there constantly. Impractible. Shunted Instrument with batteryPage 252 tried both ways apparently of no use. The new machine with double spiral spring adjustments is a success much better than the other one gone to P[atent]O[ffice].²

We tried if the mere passage of a current produced the force by making a bow of the lead but it did not.

Phosphorus Water No good.^b

32 Continuous hours work

Batchelor witness^c

[Newark,] Aug 7th 1874 6 pm

Relative Delicacy

The Pyrogallics & Gallics give very sharp writing but they lack delicacy they will make very nice salts for short circuit work & are not as yet of sufficient delicacy for long circuits but probably can be made so by further experiment. Excess of salt as yet seems to be the best for them

Solubility of Gallic although slight appears to give as good results as the more soluble Pyrogallic

Oxalic acid added to Reg Ferrid in^a which Prussian blue is said to be insoluble did not increase the delicacy of reaction nor alter the characterics of marks but somewhat whitened the paper.

Nitrate Mercury & Amm. Nitrate (chlorides form pcpt.² ) gives a delicate solution in pen on O with small normal tail it is ga little more delicate than Pyrogallics but not of a very permanent character Could some compound be p in the paper in which the mark is insoluble it would be a valuable addition

When combined with Aniline red or Magenta which was previously oxydized by Nitros acid & discoloured greatly increases the sensitiveness of the paper it is then more sensitive than regular Ferrid with little normal tailing (Tin pen on 0) as yet we have not succeeded in making it very permanent More delicate than all these solutions is Aniline red or common small crystallized Magenta the proper name of which is perhaps Hydrochlorate of Rosaniline This readily dissolves in water forming a deep red or carmine with extraordinary coloring prop[er]t[ie]s By adding to the solution in water a certain quantity of the red fuming Nitros Ac. the aniline becomes oxidized & made nearly colorless.

In this solution is added a small quantity of vegetable Ac³ the action of which I do not clearly understand of Tartarac Citric Acetic & Oxalic acids the latter of which is the most sensitive & gives the best writing

Tin pen is used on 0

The action of which is that the O forms a proto oxide or perhaps which is one of the best known reducing agents & that portion of the discolored oxidized aniline in the immediate vicinity of pen is reduced or deoxidized to its original colorPage 254 which is red at first but by contact with air it becomes dark violet The marks are very permanent The sensitiveness nearly equals if not quite Iodine, one defect of this sol is that the marks are so faint at first that they can scarcely be seen in fact at first they are not at all visible This defect we shall probably be able to get rid of^b

A combination of Pyrogallic with Gallic & Chi. Sodium gave no better results

[Newark,] Aug 123 1874

Spark. Induction Current:—

1. When you put one end of. Secondary¹ into fine brass filings & then dip the other wire into them & steadily lift it away from them a thin thread of filings follows & sticks to the wire. This thread we drew out to 2 inches. It seems as if the filings were soldered together for the time with Iron filings I got about ¼ inch if the filings were lighter we might get more Powdered Carbon will not do it at all it rather repels if anything

On 19 August 1874 Edison executed a set of seven patent applications involving multiple telegraphy designs; they werePage 255 filed at the Patent Office, along with two caveats prepared earlier, on I September 1874.¹ These designs—which came to be known as Cases 94-100² —evolved from Edison’s work of the previous eighteen months and were essentially completed before his 19 May 1874 partnership proposal to George Prescott. Nevertheless, Edison named Prescott as co-inventon when he first submitted the specifications to Lemuel Serrell. While preparing the applications, Serrell recognized their close relationship to some previous applications of Edison’s.³ He met with Edison and Prescott to discuss the matter, which led to the replacement of Doc. 451 by Doc. 466 and the adoption of wording identifying Edison as the sole inventor.⁴ Ownership of patent rights to these designs remained the basis of the agreement with Prescott, however, and became the object of extensive litigation starting in 1875.⁵

All the applications except Case 97 (Doc. 470) eventually led to patents, in most cases after modification, although Case 99 (Doc. 472) was not allowed until 1892.

[New York,] August 19, 1874^{2 a}

Articles of agreement made and entered into in this nineteenth day of August, A.D. 1874, by and between Thomas A. Edison, of Newark, in the State of New Jersey, and George B. Prescott, of the City and State of New York,³ witnesseth:

Whereas, said Edison has invented certain improvements in duplex telegraphs, for which he has executed, or is about to execute, applications for letters patent of the United States, and such applications are numbered 94, 95, 96, 97, 98, 99 and 100, and are dated August 19, 1874, and said Prescott is entitled to an equal interest in the same and others hereafter mentioned.⁴

Therefore, in consideration of the premises and the sum of one dollar in hand paid, the receipt whereof is hereby acknowledged,Page 256 the said Edison has sold and assigned, and does hereby set over and convey unto the said George B. Prescott one undivided half part of the right, title and interest of every character, in, to, under, and connected with each and all the aforementioned inventions and letters patent on the same when granted, and authorizes and requests the Commissioner of Patents to issue the said letters patent to Thomas A. Edison and George B. Prescott, as the assignees of said Edison, for the use and behoof of themselves and their legal representatives. And whereas the said Edison has also invented other improvements in duplex telegraphs, the descriptions of which have been lodged with George M. Phelps for the purpose of models being constructed, it is hereby agreed that such inventions are included in this present^b agreement, and that when the applications for patents are made,⁵ the patents to be granted in accordance herewith, and that the said Edison shall sign the required papers therefor.

This transfer is made on the following terms and conditions, which are hereby made part of the consideration in the premises:

• 1. That both of the parties shall have an equal undivided interest in all letters patent of the United States, or of any foreign countries, which may be granted for all or any of said inventions, or of any future improvements thereon made by either party, and of all extensions and reissues of any such letters patent.

• 2. That whereas Edison has heretofore expended $1,125 for models and patent fees, the benefit of which he contributes to the common interest, and waives reimbursement of that sum, or any part of it, Prescott hereby agrees to pay solely and without contribution from Edison all the future expenses and cost of specification, drawings, models, Patent Office fees, and patent solicitors’ and agents’ fees, and all other charges incident to the procuring of letters patent for any of said inventions.

• 3. That neither of said parties will sell, assign or otherwise dispose of the whole or any part of his interest in said inventions or letters-patent therefor, or any of them, without the written consent thereto first obtained of the other party.

• 4. That neither of said parties will himself manufacture, use or sell, nor grant licenses, nor the right in any way to any other party to manufacture, use or sell any of the said inventions, or any improvements thereof, or any machine embodying, or article containing, any of said inventions or improvements,Page 257 or protected by any of said letters patent, without the written consent first obtained of the other party.

• 5. No sale of any of the said inventions, and no license or right to make or use the same in any way shall be made or given, except at a price to which both parties agree in writing, and all net profits shall be equally divided between the parties hereto.

• 6. The covenants and provisions of this agreement, binding either of the parties hereto, shall also bind his executors, administrators and assigns.

In witness whereof, the said parties have hereunto set their hands and seals, the day and year first above written.

Thomas A. Edison, [l.s.]     George B. Prescott, [l.s.]

Witnesses: Harald Serrell,⁶ Lemuel W Serrell.

New York, August 19, 1874^a

94^b

• 1. To all whom it may concern. Be it known that I, Thomas A. Edison, of Newark, in the County of Essex and State of New Jersey, have invented an Improvement in Duplex Telegraphs, of which the following is a specification.

• 2. I make use of a compound induction coil through which the currents pass, and those from the sending station are balanced, but the current from the distant station is operative.² Page 258

  Inventor Thomas A. Edison per Lemuel W. Serrell atty Witnesses. Chas H. Smith Harold Serrell^c

  
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• 3. The helix a. surrounds the central part of the core that passes through the electro magnets b. and c. hence a secondary or induced current is set up in the helix a only when there is an excess of current in one of the helices b. or c. because if the current acting in b. is equal to that acting in c. and the helices are properly wound the magnetizing actions of the helices on the core will neutralize each other and there will not be any secondary or induced current in a. but when the current in one helix is greater than that in the other, the core will be magnetized and a secondary current set up in the helix a.

• 4. I avail of this feature of the compound differential induction coil to operate a duplex telegraph instrument by causing the current at the sending station where this compound differential instrument is placed to divide and act equally in both b. and c. but when the current from the distant station increases the energy of the helix b. then the induction or secondary current set up in the helix a.³ magnetizes the core sufficiently to set up a current in a.

• 5. The current in a. operates in the polarized magnet .f. toPage 259 open and close the local circuit g. in which is placed the receiving or sounder instrument h.

• 6. When the pulsation passing along the line k. from the distant station, ceases there is a reactionary current producing the core of the helix b de-magnetizes and in so doing sets up^d a second induced current in a. of opposite polarity to the first and that acting in the polarized magnet f. instantly throws the contact point of the armature the other way and opens the local circuit.

• 7. These operations in the compound differential induction coil, being borne in mind, it now becomes necessary to explain the manner of sending through such coils without producing any action on the helix a.

• 8. The key 1. in the local circuit to the magnet m. operates the lever n. that contains an insulated spring closer 3. acting against the circuit point 4. and the hook end 5. of the lever n. so that when the key l. is closed, the lever n. moves the spring 3. into contact with 4 . closing the circuit from the battery o. through 4. 3 . and the wire 6. to the helices b. and c. and at the same time breaking the contact of 3. and 5. and hence cutting out the ground wire 8. from the lever n. but the moment the lever n. returns to its normal position by the demagnetizing of m. the spring 3. closes the circuit at 5. just before separating from 4. hence there is always a metallic circuit complete for the pulsation coming from the distant station whether the circuit of the sending battery o. is opened or closed.

• 9. In order to balance the action of the sending current that divides at 10. and passes through b. and c. I introduce in connection with the helix c. an artificial line equal in resistance and conditions to the line k. hence compelling an equal current to pass through b. and c. To effect this the resistance r. is placed in the ground connection from c. which resistance should be adjustable, so that the rheostat or resistance r. equals the line, and in order to set up in c. a counter magnetism equal to that set up in b. by the static from the line, I make use of the electro magnet t. placed in a shunt that passes around c .

• 10. By this construction of compound differential induction coil and the arrangement of the connections the inductive effects of pulsations from the sending instrument are balanced and neutralized while the pulsations from the distant station operate the receiving instrument.

I claim as my invention

1st The compound differential induction coils a. b. c. inPage 260 combination with the polarized relay f. and the circuit connections substantially as set forth.

2nd The artificial line composed of the rheostat r. and magnet t . and ground connection in combination with the compound induction coil and line connections substantially as set forth.

Signed by me this 19th day of August 1874

New York, August 19, 1874^a

95^b

• 1. To all whom it may concern.

  1. Be it known that I, Thomas A. Edison, of Newark, in the County of Essex, and State of New Jersey, have invented an Improvement in Duplex Telegraphs, of which the following is a specification.²

• 2. A balanced battery is used for transmitting when the balance is disturbed. An electro magnet is used through which both the received and transmitted pulsations pass, and the^c connections are made so that the action of the current sent isPage 261 balanced, while that coming from the distant station is operative to work a balanced relay and local circuit or sounder.³

  Inventor Thomas A. Edison per Lemuel W. Serrell atty Witnesses Chas H. Smith Harold Serrell^d

  
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• 3. In the accompanying diagram drawing the battery a.b. is connected at one end to the line wire c. at the other end to the closed key e. and in the middle to the ground.

• 4. The connection 3. from the key e. to the line c . passes through the induction coil and core f. and there is a second induction coil g. around the coil f. that is in a shunt between the line connection c. and the branch h. to the ground in which branch h. there is a resistance k. that is adjustable.

• 5. The line-connection c. bifeurcates at i. passing one way through the helix l to the ground-branch h. and the other way through the helix m. to the main line s.. The electro-magnet l.m, being wound in the usual way, will not respond when the connection is made in the middle, because the current passing from c. goes one way through one helix and the other way through the other, polarizing the cores so that the armature r. is not attracted. It is important that the resistance of the branch h . and rheostat k. should be about the same as that of the main line s. so as to cause the current to divide equally at i.

• 6. It will now be understood that any current from the distant station passing through the magnet m. in the usual directionPage 262 will cause the armature to respond, whether there is any current passing through the helies or not from the sending station, and this electro magnet m. and armature act as a relay to operate the local circuit s′. and repeater sounder t.

• 7. The main battery, it will be seen, is in a local circuit when the key e. is closed, hence if both sides are equal there is no current passing upon the main line, but when the key e. is open, the local circuit is broken and the portion a. of the battery sends the pulsation through 1. and m. and upon the line s. to the distant station where the pulsation passing through m. operates the local and sounder or receives the portion through l. returning to a. through the branch h. and ground.

• 8. When the key e. is closed the induction coil f is charged, and it discharges when the key e. is opened; the helix g. that has been charged by induction also discharges and sets up in l. a current that equals that resulting from the static charge of the line, and the reverse currents are produced in the induction coils as the circuit is closed at e, thus such induction coils serve to neutralise or balance the effect of the static charge, and prevent any false pulsation on the main line, resulting from the return static charge acting in m.

• 9. It will be apparent that the closing of the key e. and the connecting of the battery b. with the line tends to set up in the line and to earth, currents of opposite polarity to those resulting from the battery a. because the positive of the one and the negative of the other are to the ground and line respectively, and this local circuit (c.a.3.e.b.) serves to maintain an unbroken connection that offers but little resistance to the pulsation from the distant instrument passing to the earth, and the resistance is nearly uniform to the current received, whether there is a current that is being sent or not.

I claim as my invention

The battery a.b. in a local circuit connected to the line, in which is a circuit breaker, a finger key in combination with the magnet l.m. branch h. and resistance k. and the induction coils f. g. the parts operating substantially as set forth.

Signed by me this 19th day of August, A.D. 1874.

New York, August 19, 1874^a

To all whom it may concern.

• 1. ^b Be it known that I, Thomas A. Edison of Newark, Essex County, New Jersey have invented an Improvement in Duplex Telegraphs, of which the following is a specification.²

• 2. The transmitting battery is connected with the line by a lever that simultaneoulsly breaks the earth connection so as not to interrupt the continuity of the circuit; the current sent divides and operates equally in two helices; in one helix there is a sliding core that moves with the armature of the other heliex and this latter^c responds to the pulsation from the distant instrument and closes a local circuit to a sounder or other receiving instrument, and there is a mechanical device that serves to compensate the attraction in one of the magnets that is due to the reverse action of the static discharge, thereby causing the forces to be accurately balanced.³

  Inventor. Thomas A. Edison per Lemuel W. Serrell atty Witnesses Chas H. Smith, Harold Serrell^d

  
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  Page 264

• 3. In the diagram of the drawing the transmitting key a. opens and closes the local circuit of battery b. to the helices of the electro magnets, c. and d.

• 4. The lever e. actuated by the armature of c. closes the line connection f. from the battery g. just before breaking the earth circuit of the line at h. so that there is always a path for the pulsation from the distant station.

• 5. The circuit from e. bifurcates at k. and a portion of the pulsation sent passes through l. and upon the line r. and an equal portion of the pulsation passes through m. to the artificial line composed of the rheostat s. and ground connection, said rheostat being adjusted to equal the resistance of the line.

• 6. The armature lever o. is inoperative by the current sent, because the action of the two magnets on the same is balanced, the attractive forces of such magnets being equal, and I make the core of the magnet m. to slide in the helix and attach it to the armature lever o. so that the cores of l. and m. may be equally energized and not influenced by the current sent, whether the armature is near the core of l. or drawn back therefrom by the spring 3.

• 7. It will now be understood that the lever o. will not respond when the pulsation sent passes through l.m. but that the armature lever o. will respond to the pulsation from the distant station because the same only acts in l. and by this lever o. a local circuit and sounder or other receiver is operated.

• 8. The pulsation sent from g. upon the line r. is increased by the static charge and upon cessation of the pulsation static charge reacts and these operations might disturb the balance between l. and m. I therefore employ the mechanical compensator formed of the spring t. and notched armature lever u. to the magnet eh hence when the current is closed at a. and the armatures of e. and u. are attracted the motion of the lever u. brings the notch at the end of such lever across beneath the v projection on the spring rt. thereby the force of the spring rt. is relieved and then again bent, and when relieved, the spring 3^C exerts its full power, and when the spring rt. is bent its force lessens the power of the spring 3. hence this spring 3. is able to resist the increase of magnetism due to the static condition of the line, when the circuit is closed and to compensate for the reaction of the static charge as the circuit at a is broken thus leaving the magnet l. entirely uninfluenced by the current sent and capable of the most delicate adjustment by the spring 3. for receiving from the distant station.

I claim as my inventionPage 265

First. The magnets 1. m. through which the current sent passes to the line and artificial line, in combination with the armature lever o. and sliding core, substantially as specified.

Second. The electro magnets c. d. in the local circuit containing the circuit breaker a. in combination with the circuit closing lever e. notched armature lever u. spring t. and armature lever o. substantially as set forth.

Third. The mechanical compensation by spring t. and notched lever u. for neutralizing the effect of^c the static charge in a duplex telegraph substantially as set forth.⁴

[New York,] August 19, 1874^a

To^b all whom it may concern:

Be it known that I, Thomas A. Edison, of Newark, in the County of Essex and State of New-Jersey, have invented an improvement in duplex telegraphs, of which the following is a specification:²

Two batteries are employed that are balanced by rheostats, and the static charge, compensated by an electro magnet, and the same poles of the batteries are connected at opposite sides of a receiving or relay magnet, hence the batteries neutralize each other in the constantly closed circuit.

A shunt wire, with a key or sounder between the centre of the combined batteries and the earth circuit, serves to destroy the balance of the batteries, allowing the one-half to act on the line, but the receiving magnet or relay is at a neutral point, where action and reaction are equal, except for the current from the distant station; to this it responds with delicacy.

In the diagram a. and b. are the batteries, connected in opposition to each other at c, and provided with adjustable rheostats at d. e. I., and one part of the circuit passes to the line f, and the other to the earth circuit at g.; the line f and earth g. are connected with the electro magnet h., the armature lever of which opens and closes a local circuit to a sounder or receiving instrument.

The rheostat r. is of resistance equal to the line, and in the connection s. from c. to g. is the finger key or lever k.

Where a circuit closing lever is used it may be the lever of an electro magnet l., or sounder, operated by a local circuit and key m.

When the connection s. is open, the currents of the batteries a. b. simply neutralize each other, the rheostats b. and e. allowing only equal currents to reach h., which currents, being Page 267of the same polarity, and opposed to each other, produce no effect in A., but leave the magnet A. free to respond to the pulsations coming over the line from the distant station.

When the lever or key k is closed, the battery balance is destroyed through c.s.k.g.r.d., and the current from b. passes most through e. f. to the distant station, returning by ground k. s. and c, and the current from a. passes mostly through the artificial line g.r., equalling the line f., but the relay h. is placed at a point where the action of the currents is balanced, as the portion passing from a. through the same to the line is balanced by that from b. through the artificial line, hence neutralizing each other.

When the lever k. opens, the forces of the batteries a. b. are brought again into opposition, but as there is a static discharge from the line which acts in h., I make use of the electro magnet p., ³ which has been charged when the batteries are active or unequally set up, producing an induced current which balances the static charge of the line, and neutralizes the effect of the same in h., thus leaving the magnet h. entirely uninfluenced, except by the pulsation from the distant station.Page 268

I claim as my invention the batteries a. and b, connected in opposition to each other in the circuit containing the rheostats d. e., magnet [-]x.^d and receiving magnet h., in combination with the line circuit f through h., the artificial line gr., and the shunt, s., containing the key or lever k., the parts being arranged for operation substantially as set forth.⁴

Signed by me, this nineteenth day of August, a.d. 1874.

New York, August 19, 1874^a

• 1. ^b To all whom it may concern.—

  1. Be it known, that I, Thomas A. Edison of Newark in the County of Essex and State of New Jersey, have invented an Improvement in Duplex Telegraphs of which the following is a specification.²

• 2. The main battery is in two parts connected in reverse in the line circuit; in the same cuircuit is the receiving instrument or relay, to which is connected a local ciricuit and sounder: One half of the battery is short circuited at the sending station by the depression of the key; simultanioulsly with this depression a local circuit is closed and a reverse current sent from a battery through the receiving magnet and in that circuit is a rheostat that is adjusted so that the effect of the battery on the line is neutralized in the receiving relay at the sending end but the battery at the distant end is free to act at the receiving station. At the same time the effects from the static charge in the line are neutralized in the receiving instrument by induction. Page 269

  Inventor Thomas A. Edison per L. W. Serrell atty Witnesses Chas H Smith, Harold Serrell^c

  
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• 3. In the diagram a. is the line passing through the electro magnet b. that operates a relay or sounder. The connection from b. is through the batteries c.d. or local circuit i.l.k. to the earth.

• 4. The batteries c. and ad. oppose each other and being equal are not operative in b.

• 5. The key e. is in a local circuit in which are the helices f. g and when the key is closed the electro magnet g attracts the armature and lever h. closing the circuit i.k. to the centre of the batteries cd. hence short circuiting c. and allowing d. to act in the line.

• 6. In order to compensate the action of the battery d. in b. the local battery l. is used and the local circuit from l. through the insulated spring m. and rheostat to the line a. is closed simultaneoulsly with the short circuiting of c. and this rheostat r. is adjusted so that the action of l. in b. equals the action of d. in b. and being in reverse the forces are neutralized.

• 7. The helices f and g being charged and discharged simultaneoulsly there is an inductive current set up in the core of f and the helix n. and that gives a secondary charge to the Page 270 helix o. that surrounds the core of b. and hence when e. is closed, the secondary effect in n. neutralizes the static effect as the line is charged, and as the circuit at the key e. is broken a reverse induction current is set up in [-]n. mneutralizing the discharge of the static charge of the line: the helices being wound so as to produce this reverse and neutralizing effect in the core of the electro magnet b by the helix n.

I claim as my invention.

First.—The local battery l and reheostat r in a shunt around the receiving magnet b in combination with the batteries c.d. shunt i. and lever h. substantially as and for the purposes set forth.

Second.—The magnets g and f and induction coils un. o. in combination with the magnet b. batteries cd and shunt circuits substantially as set forth.³

Signed by me this 19th day of August A.D. 1874.

New York, August 19, 1874^a

99^b

• 1. To all whom it may concern.

  1. Be it known that I, Thomas A. Edison, of Newark in the County of Essex and State of New Jersey, have invented an Improvement in Duplex Telegraphs, of which the following is a specification.²

• 2. The object of this invention is to enable two operators to simultaneoulsly send over one wire, in one direction, by reversal of a battery current in one instance and increasing and decreasing the strength of the current in the other instance, and the connections are so arranged that the party at the receiving Page 271 station can signal to the sender to repeat in case of inaccuracy.

• 3. By duplicating the parts herein described, four transmitting operators and four receiving operators can work simultaneoulsly over one wire, two of each being at each end. ³

  Fig: 1

  
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• 4. In the diagram Fig. 1. I have only shown the transmitting apparatus for two operators at one end of the line, and the receiving apparatus for the two operators at the other end of the line.

  4. Fig. 2. is a diagram representing a modification of one portion of the circuits.

• 5. The battery a.b. is composed of unequal elements, supposePage 272 a. to represent seventy five cells, and b. twenty five cells.

• 6. The key c. is in a local circuit that operates the magnet d. and circuit changing lever e. so that when the circuit c. is open, the battery b. is out of circuit and inoperative, but the continuity of the metallic circuit is maintained through 4.e.3. and 5. to the reversing key f. next described, and when the key c. is closed, the entire battery a.b. is connected through the insulated spring .2. and wires 3. 5. and 6. to said key f. and hence the operator of c. controls the amount of battery connected to the line and this change of power operates at the receiving station as hereafter set forth.

• 7. The key f. is made for reversing the battery connections alternately whether the whole or only a portion of the battery is thrown upon the line by the operator of c. and this key f. is operated by the electro-magnet g. local circuit and key h.

• 8. When the key h. is open as shown, the current from 5. passes by 10.11.12. and 13. out through the tell tale magnet k. to the line 1. and the return is through ground to 14. spring 15. lever-arm i. 16. and 3.

• 9. When the key f. is attracted by g. the circuit connections are reversed so that the current from 5. passes by 10.15. and 14. to ground, thence returning through line 1. 13.12.16. and 3. to battery.

• 10. By bearing in mind that one operator at c. makes his signals by changing the amount of battery power and that without breaking the metallic circuit, and that the operator at h. signals by reversing the circuit regardless of the battery power and without breaking the metallic connections, hence both parties can work without hindrance from the other, it now becomes necessary to show what instrument at the receiving station are employed, the one to respond by the change of battery force regardless of polarity and the other to respond by change of polarity only, regardless of battery force.

• 11. The polarized relay magnet m. is in the line 1. and is made with a permanent or magnetized armature, hence it will only respond when the circuit is reversed, and when it does respond by the reversal of the circuit by the operator of h. the armature lever works a local circuit and sounder n.

• 12. The electro-magnet 0. is also in the main line circuit that passes by 20. and key p. to the earth; the normal condition of this key p. is closed, but whenever either of the parties receiving, perceives any inaccuracy or interruption of the message, then the parties sending are notified by either receiver Page 273breaking the circuit at the key p. and the tell-tale magnet k. no longer responding to the pulsations of the keys h. or c. indicates to the senders that the circuit is broken.

• 13. In order to produce a receiving instrument that is operative only by the excess of the current, the spring of the armature s. is tightened to the proper degree of tension so that the magnet o. will not respond except when the closing of the key c. brings the entire battery a.b. into action.

• 14. If a reversal of current takes place when the entire force of battery is on the magnet o. there occurs a false movement of the armature s. To prevent an incorrect record or sound the local circuit and receiving instrument are made as next described.

• 15. The local circuit and battery u. is constantly operative in the receiving magnet or sounder t and hence the armature of t. only responds when an opposing current is sent through t. to neutralize the current of u. and de-magnetize the core: This is effected by battery v. and circuit that is closed by the lever s. on the back movement, hence, when s. is attracted by o. the circuit of v. being broken, allows u. to act unbalanced and give the sound, but should s. fly back on reversing the current, it will be so instantly re-attracted by o. as to prevent the circuit of v being closed long enough to neutralize the action of u. hence the signals given by the operator at c. will be correctly responded to by the receiver t.

  Fig: 2

  
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  15. Inventor. Thomas A. Edison per Lemuel W. Serrell atty Witnesses. Chas H Smith Harold Serrell^cPage 274

• 16. The diagram fig. 2. shows a modification of the receiving circuit to prevent a false indication at the receiver.

  16. The armature s. operates the circuit of the battery v′ . to the electro magnet o′. and the armature of o′. closes and opens the circuit of u′. to the receiving instrument or sounder t′. and as the magnet o′. is rather sluggish in movement its armature does not have time to move and break the circuit u′. before the armature again flies back should the circuit connections have been reversed while the key c. is closed.

I claim as my invention,

First. Transmitting two distinct messages over one wire in the same direction and at the same time, one operating by reversal of the battery current and the other by increasing or decreasing the current from the battery.

Second. In a duplex telegraph, the polarized magnet and an ordinary magnet in the same circuit, when arranged substantially as specified, so that one responds to change of polarity of the current and the other to an increase and decrease of the current substantially as set forth.

Third. The arrangement of two keys e. f. battery a.b. and reversing circuit connections substantially as set forth, to bring into action the whole or a portion of the battery and to reverse the polarity of the current passing on the line without entirely interrupting at any time the metallic circuit.

Fourth. The reversing key f., made with the arm i. springs 12. and 15 and circuit closing points 10. and 16. substantially as set forth.

Fifth. The receiving instrument or sounder in the constant circuit from the battery u. in combination with the balancing local battery v. circuit and circuit closing armature s. and electro magnet o. substantially as set forth.

Sixth. In the duplex telegraph arranged for sending two separate messages simultaneoulsly in the same direction and from the same end, the circuit breaking key p′. at the receiving end and the tell-tale magnet k. in the line at the transmitting end for the purpose set forth. Signed by me this 19th day of August A.D 1874. ⁴

New York, August 19, 1874^a

• 1. ^b To all whom it may concern.

  1. Be it known, that I, Thomas A. Edison, of Newark, in the State of New Jersey, have invented an Improvement in Duplex Telegraphs, of which the following is a specification.²

• 2. Where two persons are sending and two receiving the entire line is sometimes deranged by a signal from one of the receivers to repeat. My invention is made to allow either party that is receiving to interrupt the person sending to him so that he is thereby warned to repeat, and that without interfering with the other message that is being sent or received.

• 3. In the diagram drawing a. is the line, b. the receiving relay instrument, d. is a helix around the same core as b. and this helix is in a circuit passing to the artificial line and rheostat e. and this rheostat is to be adjusted to equal the line, so that the pulsation from the sending station acting in reverse in the helices b. and d. produces no magnetizing effect in the core, but the pulsation from the distant station passing along a. acts in b. unbalanced and either produces the sound by the armature magnet or else works a local circuit and sounder.—

• 4. The pulsation received from the distant station passes by 3. f. and 4. to the earth connection.Page 276

  Inventor. Thomas A Edison per L. W Serrell atty Witnesses. Chas H Smith Harold Serrell^c

  
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• 5. The lever f. is operated to give the pulsations that are sent upon the line and these pulsations divide at 5. passing equally through the helices g. and h. thence through the helices b. and d. aforesaid.

• 6. The helices g. and h. are of a differential polarized relay, the tongue or polarized armature lever i. of which forms a circuit breaker in the local circuit k.l.m. and in this circuit the key 1. acts to open or close the circuit and by the electro magnet m. operate the lever f and send the pulsations upon the line.

• 7. The main battery 0. is connected by wires 10. 11. to closing points 12. 13. and the reversing lever r. has springs 14. 15. and an insulated arm s. When the key 1. is operated the lever f. closes 18. and 19. and with the lever r. in the position Page 277 shown, the circuit is closed by 10.12.s.15. to the ground returning through e.a.d.b.g.h.3. spring 18. of f. screw 19. wire 20. to 14.r.13. and 11. ³ By these connections the pulsations are sent to the distant station and received there in a similar instrument. It will be apparent that at the sending station the current divides at 5. and passing through both g. and h. the polarized armature will be retained in the normal position with the circuit of k.l.m. closed regardless of whether the current sent is reversed or not, but the current from the distant station only acts in g. hence the polarized tongue is changed by the reversal of the battery connection at the distant station so that if the receiver closes the key v. he does not interfere with the party sending by the key 1. from his own station, but the battery connection being reversed the differential relay at the distant station is changed by the change of polarity in g. and the party sending the message is warned to repeat by the fact that his own magnet m. does not work because^d the polarized tongue breaking has broken the circuit of the magnet m. and it will not respond to his key 1. It is to be remarked that the receiving operator only closes his key v. sufficiently long to give the signal, and then releases it so that the parts resume their normal condition to allow of the message being again sent to him.

• 8. The [-]reversal of the polarity at the sending station does not change the balanced condition of b.d. nor make any difference in the action at the distant station because that current sent is operative in b. at the receiving station whether of one polarity or the other.

I claim as my invention

The differential polarized relay magnet g.h. and local circuit containing the key 1. and magnet m. in combination with the reversing key r. and circuit connections substantially as set forth.

Signed by me this 19th day of August A.D. 1874⁴

New York, August 19, 1874^a

To all whom it may concern.

Be it known that I, Thomas A. Edison, of Newark in the State of New Jersey, have invented an Improvement in Circuits for Automatic Telegraphs, and the following is declared to be a full and correct description of the same so far as perfected.

The object of this invention is to obviate the effects of static induction on telegraph wires so as to obtain high speeds.

The invention consists in arranging inductive devices at the transmitting station so as to increase the strength of the first part of each signal and weaken the last part.

The diagram fig. 1. illustrates my invention.

A. is the transmitting instrument. B is the battery. The wire 9. and resistance or rheostat coil R². forms a shunt to earth to preserve the continuity of the line when the battery is disconnected from the line by the interposition of the perforated paper.

C is a condenser, preferably an air condenser,¹ which may or may not be shunted by the resistance coil R¹ . according to the condition of the line.

A¹, is the chemical recording instrument. C ¹ . an air condenser shunted with the resistance coil R³.

The operation is as follows:—Page 279

At the moment that the battery B. is connected to the line and condenser C. by the contact roller passing through a perforation in the paper and coming in contact with the metallic drum, the induction current of the condenser C. which flows in the same direction as the battery current on closing it, is added to that portion of the primary current which passes to the line through the resistance R¹ . This excess of current is but momentary and ceases when the condenser is fully charged.

Were the line free from static induction when the battery is connected the dots and dashes would be recorded upon the chemically prepared paper, thus—

and the first part of each signal being heavier than the other is due to the extra current sent into the line from the condenser C. each time the battery is connected.

At the moment when the battery is disconnected, the condenser sends into the line a current which circulates in the opposite direction to the battery, and were this current recorded it would show thus:—

Now if the line has considerable electrostatic capacity (i.e.) capacity for giving a static current when the battery is connected the record will be different from the above at the receiving station but like it at the sending end, only greatly magnified.

Were no condenser used at the sending end, the record would be thus:—

The reason why the first portion of each signal is weakened is because the effect of the static induction when the battery is first placed on the line, is to set up a current in the opposite direction to it and prevent it from showing its full strength; this effect is but momentary and the dash gradually increases in depth of coloration due to the full action of the battery. If, now, the latter be dis-connected from the line, a second static current is set in motion which circulates within the line and acts upon the chemical paper in the same manner as the primal current and prevents the sudden cessation of the chemical decomposition, hence, it is evident that the effect of the static Page 280 end action is to weaken the first part of a recorded signal and add to the other part.

Now by referring to the record made by the condenser C. upon a line having no electro-static capacity, it will be seen that the first part of the signal sent over the wire is the strongest while at the other end a current of an opposite polarity is seen Now the effect of adding the condenser C. to a line having a certain electrostatic capacity is to exactly balance these opposite conditions. The extra current from the condenser added to that part weakened by the charge of the line, makes the record commence abrubtly and the second current from C. passing off the line in a contrary direction to the static current which prolongs the end of the signal, exactly balance each other and the signal abrubptly ceases and the record would be thus:—

The object of the condenser C¹. and resistance R³ is to increase this compensating charge or current should the electro static capacity of the line allow of setting up currents greater than those set up by the condenser C.

I will mention that should the condenser C³ be found in practice to set up a counteracting current, the current from the condenser C. might be short circuited after each signal by running a wire from n. to another contact roller connecting with the drum through an extra set of holes placed just opposite the space between the regular signal holes, or the pen so arranged in line of the latter holes that it would only pass through them when the signalling rollers were on the bridge or space between.²

My claim will probably be

To the condenser at the sending station applied in the line and arranged with reference to the batteries and transmitting instrument in the manner specified for increasing the first part of each pulsation and weakening the last part so as to render the marks at the receiving station sharp and distinct.

Signed by me this Nineteenth day of August A.D. 1874

Newark, N J., U.S.A. Aug. 28, 1874^a

on a new form of relay.

by t. a. edison^b

I have taken advantage of the induced currents set up within the coils of an electro-magnet at the moment of closing and opening the circuit to construct a telegraphic relay, the lever of which is worked or controlled by them.

The accompanying diagram will serve to illustrate the principle—

A and B are two ordinary electro-magnets, of equal diameter, length, and resistance. Both are included in the same circuit, together with a battery, c, and key, K.

The magnet A is permanently shunted with a resistance, s, twice as great as that of the magnet,

The armature or tongue is so adjusted that it will remain in contact with either point when the circuit is permanently closed, the same as the tongue of a Siemens’s relay when no current passes through it. It should also remain where placed when the circuit is interrupted. The operation is as follows:— Supposing that the lever is in contact with the point on the left, and the circuit be closed, the iron cores of the magnet B acquire their magnetism almost instantly, while the induced current from A, being provided with a current of low resistance formed by the shunt s and magnet sets up an opposing electro-motive force to the primary current, and delays the magnetisation of the cores of A, and allows B to attract the armature. If the current is now interrupted, B instantly loses its magnetism, while the secondary current from A circulating within the closed circuit in the same direction as the primary current, prolongs the time of demagnetisation, and this secondary or after magnetism attracts the armature to the left.

It is obvious that the greater the resistance of the circuit in which A and B are placed, the greater will be the difference in the induced currents set up by A and B. When the resistance of the current is small the induced current from B acts only upon closing the circuit, and reduces the differences, but by increasing the resistance this current is proportionately weakened, while that from A remains constant.Page 282

When properly constructed this relay is one of great delicacy.

The speed by which signals can be relayed into a secondary circuit is fully 18 per cent greater than with a Siemens relay.

A greater difference in the charging and discharging times of the two magnets may be obtained by increasing the length of A.

Newark, N.J., August 1874.^1a

To the Editor of the Scientific American: ²

In my new system of telegraphy, it would seem that power was obtained or that electricity had been passed into a new mode of motion, as with magnetism; but this is only apparent, not real, if I understand it right.

The electricity, acting by electrolysis, changes the nature of the surface of the paper, either by depriving it of some constituent, or the hydrogen, in conjunction with the metal and paper, form substitution compounds, the surfaces of which are smoother than the paper in its natural state, in the manner that the surface of rough paper is made smooth by dipping it into sulphuric acid. The strangest thing connected with this phenomenon, however, is this:

In trying to ascertain what caused the lever to move, whether it was by reducing the lead by hydrogen to a finely divided powder that acted as a lubricant, or whether the nature of the surface of the lead were changed by the absorption of hydrogen, like palladium, or whether the effect were due to the effort of the gases to escape from under the lever: I was led away from these notions by finding that platinum, with sulphate of quinine, will likewise show the movement. It then struck me that the nature of the paper was changed by the electrolysis. To test this, I had a long message received over the Automatic Telegraph wire from Washington (this wire runs in my laboratory at Newark), and recording the same on ordinary chemically prepared paper. The speed with which the message was sent from Washington was about 800 words per minute, and the colorations forming the dots and dashes were rather faint. I then passed the strip into the electrornotograph (I use this name for the want of a better one), the colorations being in a direct line with the lead point. On rotation Page 283 of the drum, and when no coloration was under the lead point the lever was carried forward by the normal friction of the paper. But the moment a coloration passed under it, the lead point slid upon the paper as upon ice, the friction was greatly reduced, and the lever moved in an opposite direction to the rotating drum.

In this experiment, no battery was connected to the instrument. This proves that electrolysis produces a change in the nature of the paper.

I afterwards fou[n]d that, if a tin pen were used to receive the message from Washington, although no marks were seen, the paper appearing unchanged, yet, on passing the paper through the instrument, the movement of the lever was more marked than before Receiving the message with a lead pen did not give so good results, although lead is the best when used, standing at the head of the twelve metals tried. The next is thallium. On paper moistened with aqueous solution of pyrogallic acid, tin is as good as thallium. Of all the solutions yet tested, potassic hydrate has been found to give the most marked results. The second best is sulphate of quinine. Third, rosaniline oxidized and discolored by nitrous acid.

A peculiarity of the quinine solution is that platinum shows an action, and shows it when either oxygen or hydrogen is evolved on its surface. With hydrogen the friction is lessened, as with all other metals; but with oxygen the friction is increased. This is so with all the metals subject to oxidation; but it appeared strange, at first, that it would show with a metal upon which the nascent gases had no effect.

With a lead point and a solution of the disinfectant known as bromo-chloralum, the evolution of hydrogen increases the friction of the paper enormously.

Silver seldom shows a movement with any solution; and when it does, it is very weak.

Sulphuric acid shows least movement with any metal.

It appears to be a matter of indifference as to the character of the metal used for the drum, which acts as one of the decomposing electrodes. Considering that the lever will close a secondary circuit under the great pressure used upon the lever, its sensitiveness to electricity is wonderful. With a delicately constructed machine, moved by clockwork, which I have nearly finished, I have succeeded in obtaining a movement of the lever, sufficient to close the local circuit with a current (through one million ohms, equal to 100,000 miles of telegraph wire), which was insufficient to discolor paper moistened with potassic iodide, or move an ordinary galvanometer Page 284needle. Messages may be read from the sound of the lever, when the most delicate telegraph magnet shows no current.

The uses of this instrument are many; in fact, it gives an entire new system of telegraphy.³

As no secondary currents are generated, as with an electromagnet, to prevent the instant magnetization or demagnetization of the iron cores, and electrolysis being instantaneous, it is obvious that the lever will respond to signals transmitted with great rapidity. I have succeeded in transferring signals from one circuit to another at the rate of 650 words per minute; hence it may be used to repeat the rapid signals of the automatic telegraph into secondary circuits.⁴

By attaching an ink wheel to the extremity of the lever, opposite a continuous strip of paper moved by clockwork, messages transmitted at a speed of several hundred words per minute may be recorded in ink. By attaching a local circuit to the repeating points, and adding thereto a sounder, it may be used as a Morse relay to work long lines of telegraph.⁵

[Newark, August 1874?¹]

armature & lever very light

The Rubber Cores should fit so that the uprights will not be moved when they are drawn in & out perhaps it would be a good idea to secure the two upright D & E together by two hard rubber studs so they couldnt spring.

One²

Hard platina points & Cores well annealed.

B 30 ohms

A. 400 ohms, or thereabts same size and length. Cores same size as shn and slotted thus³

Cores of B need not be slotted

Edison began his association with the Operator during the summer of 1874.¹ The 1 July issue contained the first advertisement for his student telegraph instrument² as well as an advertisement for the Automatic Telegraph Company. By August, Edison had agreed to serve as the journal’s science editor (Doc. 478), and the 15 August issue announced that the journal had “secured the services of a prominent electrician who will furnish us with short and pithy articles of a scientific character. ... These articles will be worded in such a manner that they will be easily comprehended by the veriest tyro in the business” (p. 4). Edison’s name was never mentioned, and his subsequent contributions were unsigned; nonetheless, it is possible to attribute authorship of many articles to him becausePage 287 draft versions of some items exist and because others are derived from Edison’s experiments and telegraph designs. His first articles appeared on 1 September, when he began a three-part series on duplex telegraphy that discussed both the historical development of the art and his own experiments (Docs. 479, 495, and 505).³ That issue also contained two shorter pieces describing his early practice instrument (Doc. 10) and an observation based on his experience with relays. One of the many subsequent miscellaneous items by Edison—on the use of platina points in telegraph instruments— is somewhat longer and more detailed than most and has been selected as a sample (Doc. 489). Edison continued to write for the Operator through the end of the year, primarily contributing short pieces. It is likely that Edison also prepared some articles that merely reprint information found in other journals or report designs of other experimenters.⁴ This kind of secondary reporting continued throughout 1875, but the extent of Edison’s involvement with the journal is unclear. See Docs. 578 and 632.

[Newark, August 1874?]

The Operator²

The Journal of the Telegraph Operators

Published in the City of New York on the 1st and 15th of each month, and sent postpaid to any part of the US on the following terms:—

Page 288Three Months.............................. 35 cents

Six Months .............................. 70 cents

One Year.................................... 1.30

On and after the 1st of Sept 1874 this journal will devote a large portion of its space to the publication of original scientific articles, written in a” clear and simple style without technical phrases or algebraic formula, and accompanied with numerous illustrations. Send two stamps for sample number Address all communication to:—

Allen & Cahill³

WU Telegraph 145 Broadway NY

New York, September 1, 1874^a

duplex telegraphe^b

It is our aim in the following article, which is to be continued from time to time, to clearly describe, by the aid of numerous diagrams, the principles of Duplex and Quadruplex telegraphy; using neither technical phrases nor algebraic equations, which of themselves require explanation and might not be understood.

The first attempt at sending two messages over the same wire at the same time in opposite directions, was made by Dr. Gind, an Austrian telegraph superintendent.

The main problem in that class of Duplex by which two messages are sent over the same wire in opposite directions, is to send a current from one station by some means into the line through its own receiving relay, without causing the cores to become magnetized or affecting it in any way whatever; but to magnetize the cores of the distant relay, untrammeled by the current sent through or around it at its own station.

This principle may be clearly illustrated if we consider that electricity travels over wires in the same manner as water travels through pipes. To work a Duplex by the transmission of water through a circuit formed of water pipes, we might arrange it as in Fig. 1.Page 289

We will suppose that this water pipe circuit is extended from Wall street to Harlem, and that A and B were engines and reservoirs, by which a current of water of any desired amount might be made to circulate in the direction indicated by the arrows.

W and X are two water wheels provided with levers, which strike between fixed points; spiral springs are secured to these levers, to keep them against the proper point when no water passes. The object of the secondary water pipe circuits, SP 1 and SP 2, will be explained as we proceed further.

Now suppose that a stream of water was thrown into the main pipe by A, that would but half fill them and traverses them in the direction shown by the unfeathered arrows. The action of this passing stream of water would be to slightly move both the wheels and take their levers from one fixed point to the other; when the water is stopped the levers are drawn back by the springs; so far the signal has been received at both the home and distant stations.

We will describe now how the wheel X is left to respond, and the wheel W prevented from doing so. You will notice, by referring to the diagram, that the water circuit SP 1 is so arranged upon the opposite side of the wheel, that the stream which is injected into SP 1 from A tends to turn the wheel in a direction opposite to that injected into MP; hence, if the amount and speed of the water in both the main and secondary pipes are equal, it is obvious that the wheel W will not move; as long as these balances are maintained any amount of water, traveling at any speed, may be sent from A into both circuits without moving the wheel W At the distant station the water moves the wheel, because none of it can circulate in the secondary circuit—SP 2.

We will now suppose that a stream of water from A is circulating in SP 1 and the main circuit, and the lever of the wheel X is moved to the left hand point, W remaining unaffected as shown before. If now the apparatus at B is so arranged that the water may be injected into the main pipe andPage 290 secondary circuit in the same direction as that injected by A, the effect of the water injected in main circuit, MP, on the wheel X, is exactly balanced by that which circulates in the circuit SP 2; but it does not prevent the wheel X from being affected by water from A.

The water injected at B into MP destroys the balance at W, between MP and SP 1, and the excess throws the lever over to the left hand point. It will be seen that it is not necessary that the water should flow in opposite directions to obtain these signals.

In the electrical duplex the secondary circuits are replaced by the Rheostat or resistance box, in which are coils of fine wire so arranged that an amount of fine wire may be inserted, sufficient to retard or set up a resistance to the passage of the current equal to that offered by the line. The water wheel is replaced by a relay having double coils of wire, so that the current passing over both the line and secondary circuits in the same direction, may pass through the two coils of the relay in opposite directions, just as in the case of the water wheel, the effect is obtained by allowing the stream of water to circulate in the pipes on the opposite sides of the wheel. The current of electricity, passing through one of the coils of the relay tends to make one of the iron cores take a north magnetism, while the other takes a south; but the effect of the current passing through the other coil is just the opposite, it tending to make a north magnetism in the same core as the other coil is endeavoring to make a south; and as the two magnetisms cannot exist in the same core, at the same time, none is formed. Thus we see that the current passing through the relay does not affect it, if the conditions of the main line are equal to those of the artificial line formed by the rheostat.

(To be continued.)²

Toledo, [Ohio,] Sept 2d 74.

Friend Al

To day I send by American Express Co. “charges paid” a small box of Chlorides, Sulphurets & Galena ores. The Chlorides are from “The Fuller” Galena from “Relief” & thePage 291 copper-stained Chlorides from The Miller Mine—all owned & operated by our Co.¹

We are now raising 20 tons pr day of Chlorides from the Fuller. The Chlorides sent you to day are not as rich as we are now raising, as they were from surface of ground Should it be necessary for more ore, you may telegraph Wm B Welles our Supt. at Salt Lake City for a sack or two, to be sent you by Express.—using my name to the telegram instead of yours.²

In reply to your questions as to Salt, Iron, Sulphur, Copper &c. There is an endless amount of them tributary to Salt Lake City

Soon as you are through testing, I will look for a report from you, and I hope your plan will result in greater yield than we got by selling to smelters³

Do you think of going to Colorado this Month? If so why not get two passes out to Salt Lake & return, and take me along with you for ballast

Hoping to hear from you soon, and with best respects to your Wife & Sister I am my dear Sir Yours Respectfully

[Newark,] Sep 5th 1874

Method of reversing a current through a relay without opening the points. ¹ Page 292

A is line passing through B & C to ground. C is polarized magnet which whether the line is charged or not, closes the local circuit for magnet F which acts as a spring for armature

A positive current now comes over at A drawing armature G to magnet B. & also lever to C. Reverse it & the polarized magnet working quicker than the ordinary open local & prevents F from pulling armature^a

Speed Regulator for clockwork.²

B is a crown wheel on the end of the 3 or 4 shaft & runs in the pinion C on which is disc E Disk E rolls on D disc which is fastened to fan shaft.

Whole carriage F is moveable & when moved to the left so that Disc E is nearest the edge of D it allows the pinion C & of course the clock work to move quicker.

[Newark,] Sep 7th 1874

Made experiment of Roman letter with one wire with the two instruments & O.K. we also found out that the extra dots could be blotted out by Caustic Potash¹ The connections for it are thus

The two rollers that transmitt the bottom of the letter are set more than a full letter behind the two top ones in order to get off the letter before the other ones get on. Two batteries are used you send a positive & neg current on the 3 & 4 pen which are recorded on all f [-]our & the same on 1. & 2 which record on all four & the way they can dbe distinguished thus: in the word ‘this’ when you send on 3 & 4 it commences on T & makes the two bottom dots but the two top pens make also two dots but which are ahead of the other two so:— now when you send on 1 & 2 3 & 4 also marks but behind but the two top marks meet the bottom ones in the right place & the consequ[-]ence is there is the same amount of dots between the letters as the letters themselves in the next letters the extra dots lap over these so in the word ‘this’

Now blot out the extra dots & you have the word ( this ) If you take the strip when they are still damp they are very easily erased by caustic Potash weak. This of course is with ordinary ferridsol 〈Cost of Insts 35.00 E&B. 12h〉^a Chas Batchelor T. A. Edison^b

Port Huron, Mich. Sept 9 1874.^a

Uncle aAl.

You told father you wanted me to come down as soon as I could.^b father wants me to go and I want to go to but mother dont want me to go, but if you have got any thing for me to do I will come [-]Right down as soon as I can get Ready answer as soon as you can.

N. Y. Sep 10/74

Respectfully referred to Gen T. T. Eckert. The employment by the Electrician¹ of a competent assistant to aid in conducting the very important experiments now going on,² was suggested by me. I am unwilling, however, to direct the detail of one of your men except through you and with your consent.³ Unless some reason occurs to you why Mr Smith⁴ should not be appointed to the position named (in which case you will return this paper with a statement of such reasons) you will please direct him to report to Mr Prescott.

[Newark,] Entered¹ Sept 1 o, 74^a

best arrangement for static²

Page 296Quadruplex: Condsr at recg end shown arranged in differential³

Caveated⁴

Duplex⁵

Transmission in same direction Duplex: which is neither differential or bridge⁶

& work dont look as if it worked

Page 297Problems Reversing with single battery Morse key⁷

also

Repeater⁸

Transmission in the same direction⁹

New York, Sept 11th 1874^a

My dear Edison—

I did not expect to get the amt promised ($100) until tomorrow, hence can only send you $25 by Bearer.

Sorry to hear you are unwell. I have nearly completed my plan for the signal etc¹ & when all is arranged will submit same to you before proceeding further—May be ready for you Monday—

The old gent (Mr H[arrington]) may be here tomorrow.

Smiles will wreath your lips & enthusiasm fill your Brain very soon— Keep quiet, but our night of suspense is over.

We will shake the foundation of things— Stearns² is entirely too unimportant to cause you a moments thought— The money & satisfaction is from another direction— I want you to understand that in all I or we do—Batchelor the faithful & Murray the persistent will be duly cared for— The old wheel horse T. A. E & I will pull together & I shall try & keep up my side— Yrs

New York Sept. 12th 1874

Dear Sir

When I last saw you I think you mentioned that you had entertained the idea of employing a Chemist.

Allow me to introduce to your notice the bearer Mr. Robert Spice ¹ with whom I have been acquainted the last two or three years and whose varied experience could not fail to be of great advantage. Respectfully Yours

[Newark,] Sept 12 1874

put on battery little at time to break up static not let it all come at once¹

New York, September 15, 1874^a

Platina Points.^b

This metal, which plays an important part in telegraphic instrumentation, was discovered in 1741, in the silver bearing sands of the river Pinto, in South America. It is generally found combined with several very rare metals, among which are iridium and osmium; the former, could it be obtained in sufficient quantities and be worked with facility, is superior to platina for circuit contacts: the latter, when in the form of an acid, is stated by St. Clair Deville, the French chemist, to be the most poisonous substance known. In a paragraph, which is now going the rounds of the papers, this chemist is said to have stated before the French Academy, that the vapor from the one thousandth part of a grain² of osmic acid, liberated in one hundred cubic feet of air is sufficient when inhaled to produce death, and that twenty-five pounds of it was sufficient to kill every person in the world, which is rather a Frenchy statement if it takes one thousandth of a grain to kill one person.

Platina is mostly obtained in the Ural Mountains in Russia, and the total production of the world does not exceed two tons per year, the major portion of which is used in chemical utensils and in the manufacture of platinic salts, such as sulphate and chloride of platinum, which are used by analytical chemists in quantitive analysis.

Platina is the heaviest metal known, it is harder than copper but softer than iron, and is found to excel in tenacity all other metals except copper and iron. Wollaston, by placing a lump of platina inside a silver wire and drawing them together and afterward removing the silver by an acid that did not attack the platina, succeded in making nearly a mile of wire Váo.ooo of an inch in diameter, which is considerably less than the finest spider web.

The platina sold in this country is all imported, and the prices are subject to a variation. On August 1st the price was eight dollars per ounce. It is fortunate, on account of its cost, that it is not necessary to use any great amount of this metal in telegraphy, though it hardly seems excessive, when we consider that one ounce will make about 250 relay points. The writer of this article having had considerable experience with this metal, has found that platina, as purchased from the dealers, is entirely too soft, and makes very bad points,³ i.e., points which are easily oxidized by the spark, and can never be made to close a local circuit of low resistance perfectly, except thePage 303 relay lever is moved with considerable force. The other defects of soft platinum are that the oxide is pressed into it, and does not clear itself, and that the oxide increases the spark to such an extent, that the relay lever does not entirely open the circuit. Should the relay points be adjusted close, and there is considerable spark, the sounder is worked merely by increasing and decreasing the resistance of the local circuit, the spark preserving its continuity. The resistance offered to the passage of the current by the spark on relay points is sometimes as low as thirty ohms, therefore the sounder is operated by merely changing from a three ohm circuit to a thirty ohm circuit. It is obvious that the sounder will work sluggish owing to a portion of the current still remaining, after the circuit is supposed to be opened.

The same effect is observed on keys, especially on those which are provided with large flat platinum wire, when thoroughly cleaned they may be worked close, but in the course of an hour they fail to open the circuit, a bright spark is noticed (due to the incandescence of the finely divided oxide), and more play must be given, or the points cleaned. By using these large flat contacts no clearance is given the oxide; in other words, the oxide is formed on the faces of the large flat points, and hammered artistically into them, without any method being provided for its removal. If the points were made small, and the lower one beveled or rounded, the oxide would have a chance to be crowded away from the point of contact. If the lower point be rounded, and the upper one left flat, the negative pole of the battery must be connected to the latter, otherwise a cup will be formed; the point connected to the negative pole becomes pointed by accumulation of oxide, and that connected with the positive, cupped.

There exists an astonishing difference between contact points made of soft platina and that which is hard drawn. The slightest pressure on the latter will close a low resistance current perfectly, the spark will be reduced more than four-fifths, and if the points are properly shaped the oxide will free itself, it being almost impossible to hammer it in.

For the reasons explained above, two flat plates or a point working against a flat plate, should never be used either upon relays or kegs.⁴ The points should never be filed, for it does not matter how fine the file is, it will leave innumerable points which are easily oxidized. They should be scraped with a sharp knife and then thoroughly burned which prevents the formation of these points.

Brooklyn, Sep: 16. 74

Dr Sir,

To save unnecessary loss of time when I come on Monday, please note the following things we shall require. Sulphydrate of Sodium sol:)

Apparatus all ready to make and pass H2S through solutions

Also please have about two gallons of Distilled water in White glass stoppered botde.

I am arranging & writing in tabular form a system of Analysis wch from experience I know to be efficient & clear.¹

I have the honour to be Yours obedient Ser[van]t

London, 25 September 1874

My dear Sir:

I am much obliged for your letter of the 1st and the extract from the Scientific American, which I shall insert in our Journal.¹ The Electromotograph seems a wonderful thing and I should be very glad of a drawing.²

If you would kindly write me a short and interesting account of your quadruplex accompanied by a drawing I shall be very glad to give it insertion.³ We are always glad to receive original communications.

I trust to hear of you soon joining the Society which is steadily increasing.⁴ Yours faithfully

NEW YORK, [September 26,] 187[4]¹

Dear Sir:

If you can find it convenient this evening will you please look over the Harrington & Edison contract ² and see if it does not cover the Duplex and Quadruplex. I also leave the power of attorney³ and will call Monday to see you. Respectfully,

GEO. HARRINGTON, Per C. B. HARRINGTON. ⁴

This editorial is representative of the many vituperative articles and editorials James Ashley published in the Telegrapher. The attacks began on 18 July 1874, ¹ in the wake of Edison’s announcement of the quadruplex, and continued for several years. Ashley’s animosity toward Edison had been simmering for at least three years prior to this, apparently rooted in the circumstances surrounding Gold and Stock’s purchase of the American Printing Telegraph Company. This acquisition had prompted Ashley and Frank Pope to sever their connections with the printing telegraph company and terminate their business association with Edison.²

Ashley focused on several issues in his campaign to undermine Edison’s professional reputation and personal integrity.Page 306

The first was Edison’s claim that the quadruplex represented a new process of multiple transmission. According to Ashley, a number of other telegraph inventors had already devised far more efficient systems of multiple telegraphy.³ The quadruplex bore “a strong resemblance to Falstaff’s lunch—’a pennyworth of bread to a most intolerable deal of sack,’” he quipped.⁴

Ashley also disputed assertions that made Edison the primary inventor of a practical automatic telegraph system, printing numerous letters which gave that honor to either George Little or Marshall Lefferts.⁵ “So far as we can prevent it, no charlatan or unprincipled appropriator of other’s property and rights in connection with electrical and telegraphic inventions shall meet with success,” Ashley promised his readers. ⁶

Through the fall of 1874 Ashley’s attacks became increasingly shrill. “We hate and despise the pretended inventors who are forever making new and startling discoveries—which are for the most part, either stolen from others or dug out of books where they have lain fallow, because they were not of sufficient importance or practicality to be worth bringing forward,” he wrote in October. Readers of the Telegrapher knew the identity of one of these fellows, he continued. “We can conceive of no meanness or moral degradation deeper than that of such a person. Any one having such characteristics should be ignominously kicked out of any respectable telegraph office whenever he sets his foot in it, or dares to bring any of his spurious wares seeking for a market.”⁷

When Western Union and the Atlantic and Pacific entered their protracted struggle over ownership of the quadruplex patents, Ashley made his view of Edison’s role in the affair clear by dubbing Edison the “professor of duplicity and qua-druplicity.”⁸ “Every person who has had dealings heretofore with Edison knows that he is utterly unreliable,” Ashley declared, “that it is a well known characteristic of his to systematically and deliberately ‘go back’ on every person who has ever endeavored to aid or cooperate in his inventions or business.” ⁹ Similar sentiments are found in almost every issue of the newspaper between January and May 1875.¹⁰

New York, September 26, 1874.

The “Organ” Business.

It has been generally supposed that the Journal of the Telegraph was the official organ of the Western Union Telegraph Company. We have shared in this belief, and have occasionally referred to it as such.² Of late, however, its character has been changed, and it has now become the personal organ of TOM EDISON and Mr. GEORGE R. PRESCOTT, the latter occupying the position of electrician to the company. It is EDISON and Page 308 PRESCOTT and PRESCOTT and EDISON, ad nauseum. It was always heavy and dull, as became an “official organ,” of which, as its circulation is mainly to the officers and employes of the company gratuitously, and as those to whom it was sent were under no painful obligation to read it, there was no reasonable cause for complaint, and it served a useful purpose in circulating the orders, tariff rates, etc., of the company.

As a personal organ, however, run in the interest of the two parties named, to advance their purposes and manufacture fame, reputation and fortune for them exclusively, it is quite a different affair, and is open to criticism. The electrical idiosyncracies of EDISON and PRESCOTT (since they have entered into partnership) are fully set forth in the columns; and if much puffing could render them valuable they would be the most remarkable scientific geniuses of the present or any former age. Unfortunately for them, outside the limited “ring” of which they are the principal members, they are not regarded as the bright and shining lights which they evidently consider themselves. However effectually they may succeed in convincing the President of the company of their preeminent abilities and attainments, electricians and practical telegraphers refuse to accord them the high position in electrical science and practical telegraphy to which they aspire. In fact, they are regarded rather as pretenders than as actual electricians and scientists.

Not content with one “organ,” however, we notice that they have adopted a nondescript sheet called The Operator, of which a few of our readers in this vicinity may have heard, as a sort of sub-organ or tender upon the larger and more pretentious sheet. Recent issues of this publication have contained such fulsome and absurd slaverings of EDISON as to make that person appear even more ridiculous than he otherwise would.³ It is generally believed that these are the productions of his own pen, as it is not reasonable to suppose that any other person would venture to expose even him to such ridicule as must be caused by the stuff that appears in its columns. The “organ” business is truly being run into the ground.⁴

[New York,] Sept 26 1874

To^a Batch

Tell Edison to look at the telegrapher Sept 26th¹ Read it Well see if he thinks best to answer it. and if so to give us some points “Solid ones” in wariting Writing, if he thinks it Worth while and gives us some points to ans his part of it we’ll take advance advise of plymouth church & “Give Em Hell” ² Allen³ & I will Work on our part tomorrow and then put whole thing together, if he thinks better not answer it why we will drop his part & may possibly answer his our part. They are a party of Damned Slanderous Damned rascals and ought to be pushed to the front at least I think so. Dam em tell him to give it to us With his cuts⁴ Monday so we can straighten up things in time

[New York,] September 30, 1874. ¹

G. B. PRESCOTT.

Started to equate duplex² about ten o’clock p.m.: No. 60 wire, eight gauge to Boston.³ Both me and Smith⁴ bothered in equating. Soon found that 60 was crossed;⁵ changed it for No. 61, eight gauge; waited till twelve o’clock to get men; started for an hour’s trial at 12.03 P.M.; messages taken from ten days’ files; no picking.

Operators at New York—Fallam, De Graw, Cook, Bennett. Operators at Boston—D. Sanford, Davin, Colson, Wood.

Weather in N.Y.: No rain; very high wind.

Weather in Boston: N. East storm; all day fine; drizzling

rain at 12:03.

Boston sent us 142 in one hour.⁶

N.Y. sent Boston 125 in one hour.

Worked well both sides.⁷

Found, after got through, that I was out of balance 380 ohms,⁸ as the wind had dried insulators on my end, while it still drizzled in Boston. Total breaks, thirty-eight.⁹ Condensers old and leaky.