This post is part of a series, Reading Time at HSNY, written by our librarians. Today’s post was written by Miranda Marraccini.

If you’re familiar with our library at the Horological Society of New York (HSNY), you might not be surprised to learn we have books in our collection about lathes, sundials, and mechanical singing birds. Maybe you’ve seen other articles where I even mention some of our more offbeat offerings, say, a volume about jukeboxes or a study of the Loch Ness Monster. But what about eyeglasses, thermometers, barometers, and weather vanes? All topics you can read about at our library!

Our collection is especially strong in the field of scientific instruments. Prominent watchmakers often manufactured other optical tools or measuring devices, and even if not produced together, these classes of implements were often sold by the same retailers. Basically, if you can craft minute metal pieces with the extreme delicacy needed to function inside a precise watch, you can make a fine telescope, say, or a really fancy thermometer.

Sometimes scientific functions can even be combined with time-telling in complicated watches. In fact, one of the most famous complicated watches of all time, the Leroy 01, contains a thermometer, a barometer, an altimeter, and a hygrometer among its 25 functions. This 2014 article from the National Association of Watch and Clock Collectors explains the story of the watch and includes a list of its complications, including Northern and Southern Hemisphere sky maps, local time in 125 cities, and time of sunrise and sunset in Lisbon.

Above, images from one book in our library, “La Leroy 01, Ultra Compliquée,” in French, show a secondary dial on the famed watch with nine indications (of the 25), including hygrometer, barometer, and thermometer. Image 1 shows the dial, and image 2 explains how the hygrometer works inside the movement.

The hygrometer measures humidity using an actual human hair–as anyone knows who has tried to attend a formal wedding in August, hair’s length changes with humidity. The alteration in length can be quantified and paired with an indicator ranging from zero to 100. At least according to my crude translation, this book also claims that blonde hair works better for measuring humidity, proving that blondes not only have more fun, they are also better meteorologists.

Because of the overlap between horology and scientific instrument manufacture, our collection contains a number of books about scientific instruments, particularly those that measure the weather, including “A Treatise on Meteorological Instruments” (a reprint of an 1864 volume); “English Barometers 1680-1860”; and the intriguingly named “Barometers: Wheel or Banjo.” (Why not both? You’ll have to visit our library to find out.)

In our archival collection, we hold the papers of the Henry J. Green Company, manufacturer of meteorological and scientific instruments. James Green and his nephew Henry J. Green were important barometer makers and sold to institutions like the U. S. Navy and the U. S. Weather Bureau. A generous relative donated the company’s papers to HSNY a couple of years ago.

James Green, an English immigrant, started manufacturing “philosophical instruments” in Baltimore in 1832 and moved to New York a few years later (and to Brooklyn in 1890). Green’s bread and butter was the mercurial barometer, in which the level of mercury in a glass tube indicates how strongly the atmospheric pressure is pushing down outside the tube. Higher air pressure generally means clearer weather, while low pressure means clouds and rain, and extremely low pressure, the kind that makes your ears pop, means you’re inside a hurricane. After manufacturing quite a lot of barometers, Green quickly expanded into thermometers, used for meteorology and in laboratories.

In 1877, the United States Signal Officer, part of the U. S. War Department, wrote to Green asking for a volume discount, and Green obliged (image 3). Prices ranged from $3.00 for a pocket thermometer ($2.50 with the discount) to $100 for an observatory barometer. Green and the Signal Officer, actually a series of officers and administrators, carried on a robust trade throughout the 1870s and 1880s.

In 1883, the Chief Signal Officer requested some custom glass bulbs and glass tubing for a type of thermometer called a Jolly air thermometer (it’s not particularly cheerful; just named after someone called Jolly). He included a sketch of what he wanted, with dimensions (Image 4). A later letter from Green shows a particularly elaborate Gilded Age letterhead, bearing an image of a medal that Green received at the International Fisheries Exhibition, a kind of World’s Fair in London in 1883 (Image 5).

Many of the letters in the collection are all obliging, full of praise for Green’s instruments. However, like any business, there were unhappy customers. In image 6, the Chief Geographer from the U.S. Geological Survey writes to Green: “I regret to say that the cisterns of two of the barometers sent me some time ago, are leaking so badly that the instruments are temporarily worthless…the loss of the observations will cripple our work.” He requests a new barometer “at once” and ends his letter “Hereafter I must beg you that you put your instruments in such order that difficulties of this kind will not arise as they cause very serious trouble.” I don’t know how this particular situation resolved.

In addition to the Navy and Weather Bureau, Green corresponded with the Surgeon General, U. S. Patent Office, U. S. Geological Survey, and university observatories across America and Europe.

By the 1950s, H. J. Green was manufacturing barographs, rain and snow gauges, anemometers, wind vanes, thermographs, hygrometers, evaporimeters, and psychrometers (no, none of those are made up). Did you know there was so much to quantify about weather? A midcentury catalog (image 7) shows two types of barometers, a mercurial barometer (contains mercury, obviously) and an aneroid barometer (one that doesn’t use any liquid inside). Another page shows wind velocity and direction indicators, including ornamental wind vanes at right (image 8). We might not think of weather vanes as scientific instruments, but they do report data about atmospheric conditions, namely, which way the wind is blowing.

Another curiosity is a book whose title translates to “Church Steeple Weathercocks and Weather Vanes in Everyday Life and in Art History” (it probably reads better in the original German.) Josef H. Schröer, the book’s author, founded a museum of weather vanes from his own collection. His wife, Ina, writes in her foreword to the book that the “specimens” joined the family gradually over 40 years, and that over the course of that time “they…also crept into my heart!” I can see this must be true because the book also includes a poem on the same topic by Ina.

Ina Schröer goes on to discuss the Christian symbolism of roosters and why they appear on top of churches. Although the book is exhaustive, there isn’t a huge amount of variation among the vanes. There are a lot of roosters and crosses, with a smattering of other religious figures, like the archangel Michael battling Satan (image 9). I was surprised to discover, however, that the author included his own accomplished creations in another area: baking bread in the shape of weather vanes (image 10).

We’re verging on another subject here, the connection between horology and food, which I think deserves its own article. Let me know in the comments if you agree, because these scrumptious-looking bread chickens are making me peckish.

Reading Time at HSNY: You Don’t Need a Weatherman

Reading Time at HSNY: Ex Libris