I’ve never seen a sextant like this one before, but I’m no sextant expert so I alerted someone who is a true authority on sextants about this sextant. He told me he had never seen anything like it either. One of the two wheels contains four small glass windows, and I suspect each of them is tinted to a different degree. It would appear that the idea here is that the user can rotate this wheel to align one of the four tinted windows with a peephole in the other wheel, and then sight objects through the sextant’s mirrors. My sextant expert friend pointed out that there are situations in which one might want a wider field of view than is obtained using a sextant telescope. He also told me (to borrow closely from his message to me) that telescopes were seldom used in small vessels before 'zero magnification sighting tubes' became the norm, and that Captain Cook on the voyage of the Resolution had wondered whether the use of a telescope had anything to offer. My friend also said that he himself recently was sailing in rough seas and found that he needed to remove his sextant’s telescope to bring the sun down and then replace the telescope to make his final readings. So, as best I can figure, it would seem that Brandis #3249/USNO #836 was made for use in situations in which high precision measurements were not needed or were not possible. If anyone thinks they’ve got a better explanation, or if my sextant expert friend finds that I’ve misunderstood what he has tried to explain to me, I am quite happy to be corrected.
Another thing that is very interesting here is that, as I mentioned above, the firm name marking of the box does not match the firm name marking of the sextant. It could be that Brandis #3249 is just another example of a sextant that got separated from its original sextant box, but I’m not so sure that is the case. Brandis #3249/USNO#836 fits snugly in the box it is in, and the box does not contain the usual telescope holders, so the box appears in this regard to have been made to accommodate the sextant it currently houses. On the other hand, the sextant box has a holder for shade glasses that this sextant does not have, and so in this respect the sextant and box don’t match. In a previous post, I showed that the change from the ‘Mfg Co.’ firm name marking to the ‘Inc.’ firm name marking on Brandis sextants occurred between the making of Brandis #3243 and Brandis #3331. Here we have in Brandis#3249/USNO#836 a sextant with the earlier firm name marking in a box with the latter firm name marking; I wonder if what we see here is sort of like a missing link fossil that in this case captures that transition in the Brandis firm name. It seems possible, though not provable, that this sextant and sextant box came out of Brandis during the period it was changing firm names, so the sextant got one name and the sextant box, the other.
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Additional thoughts:
(5/7/15) Perhaps what I took to be a holder in the box for (unnecessary) shades is in fact a holder for spare mirrors, though mirrors would seem to be rather delicate items to carry as spares. Also, it occurs to me that the two-wheeled contraption could have been made at Naval Observatory to replace the usual telescope bracket, so perhaps this was some sort of experimental instrument cooked up at the Naval Observatory.
(5/24/15) After making this post, I came upon a 19th century octant that is being offered for sale by Antiques of the Sea (http://www.antiquesofthesea.com/instruments.html), a nautical instrument dealer, shown below. This instrument uses a peephole sight rather than a telescope; the dealer also is selling another quite old double peephole sight octant. So, while Brandis #3249 isn’t your typical Brandis sextant, peephole sight instruments were apparently nothing new back when it was manufactured.
Comments, corrections, additional relevant facts, differing viewpoints, etc., are always welcome (no one will be banned, blocked, or castigated for offering differing opinions). Send corespondance to gardnersghost@gmail.com
