Looking for Love and Loss on the Margins of an Ottoman Timekeeping Manual

An 1824 manuscript housed at the Süleymaniye Library in Istanbul presents the reader with dense walls of instructional text on the proper uses of the quadrant: the method by which celestial altitudes are measured, and how to calculate time accounting for the changing seasons. Yet, on the margins of the manuscript, something else appears: "Do not have intercourse on top of your possessions for [your child] will turn out an unbeliever; and if you go to your wife on a Tuesday, the child will grow to be a martyr, will have a pleasant smell, be carefree, with a tender heart, and eloquent tongue."¹

This piece of marginalia, offering astrological advice on the right time to procreate, is found in Süleymaniye Yazma Bağışlar MS 5569—a manual on the use of the rubʿ, or portable quadrant, copied by one Yusuf bin Ziya. What makes this particular manuscript noteworthy is the relationship between the main text and the marginalia. In this essay, I analyze this relationship to show how we can read an instructional manual for a timekeeping instrument as a repository of expectations for futures past.

According to a list compiled by Feza Günergün from the IRCICA catalog of Ottoman astronomy manuscripts, there are about 400 extant manuscripts on astronomical measuring instruments copied in the Ottoman Empire between 1400 and 1900. A majority of these manuscripts deal with portable quadrants, much like MS 5569.² These quadrants were often made of three parts: one face

Figure 1.

Detail from the illuminations of Mustafa Ali's sixteenth-century Nusretname showing an Ottoman munajjim observing the altitude of celestial bodies with the help of a wooden quadrant. Topkapı Palace Museum Library (TSMK) Hazine 1365, fol 5b. Image courtesy of Milli Saraylar İdaresi Başkanlığı.

of the quadrant featured the astrolabic quadrant (rubʿ al-muqantarat), effectively a quarter-astrolabe used for observing the positions of celestial bodies. The other face was the sine quadrant (rubʿ al-mujayyab) which offered an orthogonal grid that enabled trigonometric calculations. Finally, a movable cord with a bead at its end, called the ḫayṭ-ı murī, was attached to the apex of the quadrant and simulated the effect of the Earth's daily rotation, similar to the movable rete of an astrolabe.³ By the nineteenth century, these devices were increasingly made out of lightweight wood, which made them much cheaper to produce and far more easily transportable.

Seafarers, including merchants and imperial navigators, used quadrants to ascertain the location of ships at sea, and astral scientists used them to determine the position of the sun, the moon and other celestial bodies. In the Ottoman Empire, manuals on quadrants were consulted primarily by muwaqqits—the timekeepers of imperial mosques—who used the measurements from the quadrant to calculate prayer and fasting times as they changed with the seasons.

The first page of this quadrant manual begins with sketches for an illumination that have not been colored in. After a besmele, the main text of the manuscript begins on folio 1B with the phrase, "Know that the rules of measuring altitudes from the muqantarat side are always this way. So pay attention to the way!"⁴ The text then proceeds with instructions on determining celestial altitude—the angle of a celestial body, usually the sun or the moon, measured upwards from the horizon—which is necessary for the calculation of time. Folios one to four offer instructions on the use of the muqantarat side, while folios four to seven offer instruction on the use of the mujayyab side.

Starting on folio 3v, and continuing on folios 4r and 6v, detailed advice on the auspicious and inauspicious times of copulation begin to appear on the margins.⁵ "Ya Ali!" the marginalia on folio 6v reads:

If there is honey, raisins and vinegar in a house, the angels will pray there. Ya Ali, do not go to your wife on the first of the month, if you do so...