The Oxford Companion to Art ed. by Harold Osborne (review)

Books Basic Optics and Optical Instruments. Prepared by the Bureau ofNaval Personnel. Dover Publications, New York, 1969. 480 pp., illus., paperback. $3.00. Reviewed by: Grace Marmor Spruch* The introduction to a book of Escher's graphics relates how the artist was told by a crystallographer that the symmetries he employed did not comprise all the symmetries known to scientists. Escher thereupon took note of the ones he had missed and proceeded to apply them. Technological features have been taken on by a number of branches of art and in those branches talent seems to be only one of several requirements for an artist. Some scientific skills are not easy to come by. For learning optics, a physics textbook is the usual source. But reading a physics textbook is not easy; the language, concepts and approach are aimed at persons with mathematical background. Basic Optics and Optical Instruments is not a physics text; it is a training manual prepared by the Bureau of Naval Personnel and as such it is an excellent source from which artists can learn optics and much more besides. The book treats not only standard optics, for there is a long section on the lathe and other machine tools, with even the proper cutting speeds for different materials listed. The book is a kind of department store-everything under one roof. And, as in a department store, there is much one can do without: chapters on gun telescopes, magnetic compasses and sextants. But since everythingiscarefullycompartmentalizedandclearly labeled, it is easy to find the items ofinterest and the quality of those items is high. After the opening chapter on advancement to Opticalman third and second class, the next chapter treats optical glass: its structure, composition, properties, the reasons for its transparency and its manufacture. Little ofthis kind ofinformation is to be found in physics texts, where in order to present theoretical principles without distraction, situations are so idealized that the material from which lenses are made is rarely mentioned. For those who will use optics with their hands, however, it is of value to know when to employ glass and when plastic. Some of the tests for strain may even serve as inspiration. The next chapter, on the characteristics of light, an excellent treatment of such qualities as wavelength , frequency and speed of light, provides for an understanding of transparency, opacity and how objects are seen. Using an egg and an egg-shaped piece of cardboard as examples, the manual points out how the different reflections in the two cases leads to our detecting differences in shape and texture. All this the artist knows by intuition. Understanding it, however, can enable him to produce exactly what he wants in regions where he lacks experience and, hence, intuition. A section on transmission and absorption of color contains a * Physics Department, Rutgers University, Newark, N.J. 07102, U.S.A. 14 189 clear explanation for the fact that mixing blue and yellow paints produces green while mixing blue and yellow light beams produces white. Suggestions for do-it-yourself experiments involving flashlights and cellophane are included. Optical illusions and such natural phenomena as rainbows are nicely explained. From qualitative discussions the book goes on to a quantitative treatment of image formation by lenses and mirrors. The mathematics is on a level that anyone can understand and calculations are carried through to completion. A chapter on basic optical instruments includes the eye and binocular and stereoscopic vision. Since reviews seem to require complaints, I will list a few but I regard them as minor. Typographical errors, while present, are no more numerous than elsewhere; more serious is an error ofthe 'slip of the typewriter' variety where emit appears instead of transmit in 'Objects which emit no light are designated as opaque'. An exposition of the theories of light is perhaps the weakest part of the book, suffering from the malady that usually afflicts physicsfor -layman expositions: condensation renders them confusing, if not meaningless. It is extremely difficult to treat highly abstract theories in nonmathematical terms and it is questionable whether anything is to be gained from presentations that emerge simply as phraseology. In the same vein, a method for measuring the...