Another installment in the Naval Observatory sextant number story. In trying to come up with a chronology of issuance of Naval Observatory (N.O.) numbers to sextants based on the USNO Annual Reports for 1916-1930, one question I wondered about was when the assignment of N.O. numbers to sextants began. Some Googling led me to a book sold through Amazon containing a collection of the USNO Annual Reports from 1884 to 1900, which I ordered and just received this afternoon. The Annual Report for 1884 contains this statement, apparently from the superintendent of the observatory:
“An effort as been made at the Observatory to establish a system by which all sextants and octants for issue to the Navy shall be examined and corrected, as far as practicable, and their errors, as well as those of the instruments used for meteorological observations be furnished to the navigators of vessels from this place so that there would be a continuous record of every instrument supplied by the Bureau of Navigation. I recommend that all instruments found to be worthless be broken up, in order that they be rendered incapable of doing harm to any one…”
From this, it seems like 1884 marked the start of the assignment of N.O. numbers to instruments inspected at the Observatory. And sure enough, the USNO Annual Report for 1886 contains the only actual discussion of the assignment of N.O. numbers to instruments in any of the USNO reports I’ve read, and I’ve read through the whole pdf of 1916-1930 Annual Reports and some from the 1904-1913 period, as well.
The discussion of assigning N.O. numbers in the ’86 report isn’t in a section devoted to sextants, however, it’s in a discussion about the testing of thermometers:
“…The thermometer is marked on its stem with the hall mark (shown in the annexed cut) and with the Observatory number by means of a writing diamond. A certificate, such as that which follows, is sent with the thermometer when issued or returned after being tested”.
A jpg showing this part of text and the example certificate, N.O. #66 is attached.
I noted in a previous post that a few USN chronometers/torpedo boat watches apparently were assigned N.O. numbers; whether there was a single set of numbers for different types of instruments, or parallel sets of numbers for different types, I don’t know.
Note added: I've gone through my 1884-1900 USNO Annual Report Collection and I count a total of 287 clinical thermometers for hospitals certified at the Naval Observatory, all between 1886 and 1888; there is no mention of clinical thermometers after 1888. Also, I looked at all the chronometer trials results listed from 1884-1900 and see no chronometers having N.O. numbers; the 16 'old' chronometers with N.O. numbers tested in 1920 (see in reply #100 above) remain the only ones I've come across.Why does any of this matter? The reason is that we’d like to know what year the Naval Observatory stamped a sextant with N.O. number 1542. If the Naval Observatory started stamping N.O. number into sextants shortly before WWI, then from the information published in the 1916-1930 USNO Annual Reports, I would think (see my earlier posts on this thread and
on this other thread) that sexant #1542 was a WWI-era sextant and probably left the USN either by transfer to the merchant marine or by sale as surplus equipment some time probably after 1928. But it looks as if the observatory started marking sextants with N.O. numbers well before 1900, making it conceivable that sextant #1542 saw action in the Spanish-American war, say. The 1884-1900 Annual Reports also say that unwanted equipment was disposed of on several occasions during this period, so there would have been plenty of opportunities for one of these sextants to make its way to Gardner Island with Thurston Howell the first.
From what I’ve seen so far of the pre-1916 reports, the number of sextants that could have been assigned N.O. numbers probably got no where near 1500, or even 500; we also have clues about the chronology of issuance of N.O. numbers from the dated eccentricity certificates of sextants that are in museum collections or that have turned up on ebay. All the same, the story coming out of the 1884-1900 USNO Annual Reports makes the job of coming up with a chronology of issuance of N.O. numbers to sextants more uncertain.