I have recently developed a theory that many, most, and perhaps nearly all of the larger aperture reflective professional astronomical telescopes in the world, built before say, 1970, may suffer from the fact that they were often polished in a horizontal position and tested in a vertical position resulting in astigmatism of varying magnitudes being polished into the mirror. This then brings in to play my favorite topic,
nodal aberration theory. The figure below is one such example and historically is the first known physical evidence of binodal astigmatism. For more on this topic, see the
short newsletter article that I wrote at SPIE's request following my talk at SPIE annual meeting.
Figure 1. Through focus photographic plate taken with the 90” telescope of the Steward observatory, located on Kitt Peak in the mid-1970s. The boxes to the left and right are highly magnified regions of the star plate showing the ellipticity of some of the star images. The two foci of the overlaid hyperbola are the locations of two positions in the star field with no astigmatism – labeled by Prof. Roland Shack, the discoverer, as binodal astigmatism, which led to a complete nodal theory of optical aberrations, my Ph.D.
But, that is not where this blog entry will go. What was brought to mind was to answer the question, how many large primary mirror based telescopes were built before 1970? This brings us to “Early American Observatories” by Willis L. Milham, which, happened to be on a recent book list that passed my way. The “book” was in fact a collection of articles that were bound together for the author, who was “The Field Memorial Professor of Astronomy” at/by Williams College (and perhaps now you are in a position to guess where the first observatory is claimed to have been installed). This book became the basis for two much shorter articles of the same title published in Popular Astronomy in 1937, (Vol. 45 (if my Roman numerals are right)).
This path of investigation illustrated, yet again, just how fascinating it is to have the Internet. The articles by Milham are a bit of a ramble, with more than a lot of trivia of who was a professor where and for how long. It seems that although Europe was actively developing observatories, with the likes of Herschel, America was not. In fact, Airy, of Airy disk fame, is quoted as saying that in 1832 America had not a single observatory. Not quite true it appears, but close. Now, here is where Milham fills in for us. He researched to find there were 11 legitimate candidates to be named early observatories in the U.S. erected by 1840. Where “legitimate” is an attempt to rule out a 3” telescope in a wood shed, which at this point in time is in fact nearly a legitimate observatory, compared to the alternatives. The article is readily found from the Google Scholar web site (
www.scholar.google.com) using a search like:
Milham, “Early American Observatories”.
The outcome being that the Observatory at Williams College is not only the first, but, it is still standing (okay, it was still standing in 1937 when the article was written). Milham has a quote from then President John Quincy Adams, in 1825, on the topic of forming universities in America (apparently there weren’t many of those either) that “Connected with the establishment of a university, or separate from it, might be undertaken the erection of an astronomical observatory, with the provision for the support of an astronomer, to be in constant attendance of observation upon the phenomena of the heavens …” However, as it turns out, Congress never really bought into this idea, at least for the purpose of science. The U.S. Naval Observatory was the first government-sponsored “observatory”, but I believe (and more research is needed) that it was created to help with surveying. In fact, it appears that anyone in America who wanted the title “astronomer” on their business card in the 1800s would also most likely have the title of surveyor and often minister. It is impressive then, to me, that the Lick Observatory (a subject of some later blog) was up and running in 1890. If you ever find yourself in a used book store with any scholarly content, keep an eye out for the publications of the Lick Observatory, typically with publish dates in the 1890s. These are great coffee table additions (or, if you decide not to, let me know where you saw/left it).
Along the way, Milham brings out a topic that has gotten more coverage recently, the importance of clocks, or, in that period, chronometers. In and around 1840, it was still difficult to determine longitude as this can only be done well with a highly accurate clock, which did not yet exist. This little detail causes Milham, and now me, to detour and, in his case, tell a long story of the details of placing the Mason-Dixon Line. I assumed Mason and Dixon were politicians. But, no, they are astronomer/surveyors! Who knew? If you like to clutter your brain with trivia, this is an interesting subject to pick out of the Milham article. As it turns out then, the funding of astronomy was made in the interest of surveying and a better determination of the all important property line. I find even now, I typically need a surveyor to keep my neighbors at bay.
The article by Milham, for me, has more diversions than information on the primary mission. In fact, it told me nothing of large reflecting telescopes, since, there are not any in America, yet. Another example of a diversion that Milham creates, again related to time, is the topic of “time balls”, I assume like the one that remains in New York for use at New Year’s. Again, the Internet can provide a whole series of articles on “time-balls” of the period, which were used to synchronize clocks over a large area for the purpose of accurate surveys, if I have it right. As if this is not bad enough as a distraction, the first time balls were to be made by Goodyear (yes, that Goodyear), who had just figured out how to vulcanize rubber from the Amazon. I am someone who has a substantial collection of books written by travelers to the Amazon, particularly in the 1800s, and as a result, I have read much on the discovery of rubber. So, here it comes back in the form of time balls. This all feels like an episode of James Burke series "Connections", by far the best use of a TV I ever found.
The final diversion for today’s blog is giants. Now, this diversion is not directly Milham’s fault, but he contributes. It seems there was a Dr. Humberd, who upon crossing paths with Milham, got enough of his attention to warrant receiving his own personally inscribed copy of Milham’s book. This, of course, is the copy I have come to own. Based on a prior experience, I now always look in the front cover of a book like this to see if there are any random names from inscriptions or book plates. I search those names on the Internet, which turn into a full 1-hour talk on optics (I may blog sometime the first time I did this). Humberd was a medical doctor who, yes, specialized in giants. His claim to fame was to have reported the tallest (and apparently then dead) person in the world at 8’3”. The person was most probably only 7’3”. He also went to the trouble to paste in a cutout from a 1938 editorial advocating U.S. postage stamps of medical doctors. Here, one is presented with yet another name to trace: Manasseh Cutler, “A versatile man, Cutler collected painstaking astronomical and meteorological investigations … he died in Hamilton, Mass., July 28, 1823.” Finally, in a rare instance, this book also has a handwritten letter from Milham to Humberd. The letter basically says to Humberd that the “observatory” he had inquired about was probably not for astronomical purposes but instead was erected to keep a watch for Indians!
I am out of time ... back to the present. Perhaps I’ll run down Cutler to see where he takes us, in the future. To close, I encourage you to check out the Milham link. There is a write-up of Ralph Waldo Emerson’s visit to the Hopkin’s Observatory on the campus of Williams College and, in fact, a wealth of just plain interesting material on the 1800s. Although my “catalog” says I have it, I have not been able to locate an article by Elias Loomis in Harper’s New Monthly magazine in 1856 titled, “Astronomical Observatories in the United States” in my collection or on the Internet. This was referenced by Milham and many others along the way.
The next blog entry will at least be initiated from the “Catalogue of the 16th Annual Exhibition of the Physical Society of London and the Optical Society, January 5, 6 and 7, 1926”, assuming I do not get distracted by something else first.
Figure 2: The Hopkins Observatory (in 1938), at Williams College, constructed from 1836-1838.
