Saturday, December 3, 2016

Brandis Sextant Taxonomy, Part Two: High Grade Sextants

A second sextant type that appears in Brandis Catalog No.20 is the ‘U.S. Navy High Grade Sextant’.  The catalog listing tells us that it provides a 10 second measurement precision and has a frame with a 7-inch radius.  Its frame pattern consists of four radial arms crossed by two curved stiffener braces, making it readily distinguishable from Brandis surveying sextants.


A few weeks ago a very nice example of a Brandis high grade sextant came up for auction on eBay. Two photos of that sextant taken from the eBay listing are reproduced below.  Its frame pattern and radius matches the high grade sextant listed in Brandis Catalog No. 20, and its arc scale is marked in 10 minute intervals, which is a sensible way to graduate the arc scale of vernier sextant meant to be read to a precision of 10 seconds. Unfortunately, none of the eBay photos provided a view of the vernier scale.  Its eBay seller reports its Brandis serial number to be 2864 and says that it does not have a U.S. Naval Observatory number [1].





I’ve had little luck finding other Brandis sextants that match the high grade sextant listed in Brandis Catalog No. 20.  A Brandis sextant with serial number 3193 in the collection of the Smithsonian museum has been a long-standing puzzle to me in this regard.  According to the description of this sextant on a Smithsonian web site [2], Brandis #3193 is a standard U.S Navy high grade sextant, or at least started out as one:

This is a standard "U.S. Navy High Grade Sextant" that was made in the period 1914-1916 and modified in the early 1920s. It has a Willson bubble telescope, a Fischer rapid release lever, a drum micrometer, an electrical light over the divided arc, and a battery in the handle. The National Bureau of Standards transferred it to the Smithsonian in 1957.

According to the Smithsonian, the frame of Brandis #3193 has a 7-inch radius and the photo that accompanies this description shows that the frame has four radial arms and two curved stiffener braces, like the high grade sextant in Brandis Catalog #20.  But while Brandis #3193’s frame is of the same size and has the same pattern as a Brandis high grade sextant, a detailed photo reveals that its limb has a rack, i.e., a series of teeth, at its periphery, and that its arc scale is divided only in one-degree intervals (a portion of this photo is reproduced below).  A rack is a component of the fine positional adjustment mechanism for the index arm of a micrometer sextant, but not of a Brandis vernier sextant, whose index arm is adjusted using a clamp-and-tangent screw mechanism. In the above photo of Brandis #2864 in its box, the clamp can be seen on the sextant's arc, connected to the index arm by the tangent screw.  Once the clamp is fixed to the arc (the thumbscrew for doing so is visible in the photo), turning the tangent screw causes the index arm to rotate clockwise or counterclockwise around its pivot point depending on which way the tangent screw is turned.  One-degree arc scale markings are suitable for Brandis #3193 because the micrometer drum scale is read to determine where a measured angle falls between those one-degree scale markings to the desired precision.  But the arc scale of a vernier sextant must be marked in fractions of a degree to be read to a precision useful for celestial navigation; the photo of Brandis #2864 shows us that the arc scales of Brandis high grade sextants are marked in 10 arc-minute intervals.  So Brandis #3193’s arc scale, like its rack, is not a feature of a Brandis high grade vernier sextant.


Are the rack and arc scale modifications to a Brandis high grade vernier sextant frame?  When I compare the limb of Brandis #3193 to that of Brandis #2864, it doesn’t seem to me that the latter can be a modified version of the former.  Could it be that the rack and one degree arc scale are original to the frame, i.e., that the frame was made to be an aeronautical micrometer sextant frame?  If Brandis serial number 3193 appears somewhere on the frame, the answer is ‘No’, because Brandis serial number 3193 corresponds to a manufacture date no later than 1917 according to the Brandis serial number chronology [3].  From what I’ve read, Brandis didn’t start making micrometer sextants until after the first World War, when it began manufacturing air navigation sextants.  Curiously, I can’t find a Brandis serial number on any part of the sextant that is visible in my detailed photo; normally the serial number appears on the front of either the limb or the index arm.  However, front side of the sextant’s index arm is marked with the ‘Brandis & Sons Mfg. Co.’ firm name that Brandis operated  under for several years ending in 1917 [4], and so the index arm, at least, was made no later than 1917.  Could it be that this sextant consists of a pre-war vernier sextant index arm attached to newer, micrometer-friendly sextant frame?  I don’t find this idea particularly appealing: if you’ve gone to the trouble of making a brand-new micrometer sextant frame, why put the index arm of an old vernier sextant on it?  I hope to eventually solve the puzzle of how and when this sextant was made but for now I consider the jury to be out on what kind of sextant this is and what serial number, if any, it was assigned by Brandis.

The trail grows even colder after Brandis #3193.  None of the many other Brandis sextants I’ve seen match the features of U.S. Navy high grade sextant in Brandis Catalog No. 20.  A few of them don’t quite fit into any of the types of sextants I can classify, and one or two of these sextants could potentially be later versions of a Brandis high grade sextant, but I will leave discussion of these sextants for a later post.  There is a hint that a sextant box owned by Tighar may have once held a Brandis high-grade sextant.  At the Tighar web site there are two photographs that provide side-by-side comparisons of three sextant boxes [5].  Two of these boxes still hold their original sextants, both of which appear to be surveying sextants.  The third sextant box also holds a surveying sextant but according to Tighar this sextant is not the box’s original occupant.  Markings on this third sextant box indicate that the original sextant it held was Brandis #3527/USNO#1599.  This third sextant box is larger than the other two, and since high grade sextants are larger than surveying sextants I wonder if Brandis #3527/USNO #1599 was a high grade sextant [6]. This is a question that can potentially be answered because there is a Naval Observatory inspection certificate attached inside the lid of this sextant. That certificate, if it is for Brandis #3527/USNO #1599, quite possibly indicates its type.

Comments, corrections, additional relevant facts, differing viewpoints, etc., are always welcome (no one will be banned, blocked, or castigated for offering differing opinions).  Send to gardnersghost@gmail.com
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[1] Personal communication with eBay seller
[2] http://amhistory.si.edu/navigation/object.cfm?recordnumber=123457
[3] See the earlier post titled 'What do the Number 3500 and 1542 Tell Us?,  Part Two'
[4] Ibid.
[5] See the 'Box Comparisons' photos at:  https://tighar.org/wiki/Sextant_box_found_on_Nikumaroro
[6] Tighar indicates that a sticker inside the box suggests that it once held an aeronautical bubble sextant.  I don’t think the box was enlarged to hold a bubble sextant, which had additional components.  Although a few small newer (lighter colored) pieces of wood are seen in the interior of the box, the external walls of the box are of a uniform, darker color.

Saturday, November 5, 2016

Brandis Sextant Taxonomy, Part One: Surveying Sextants

In toiling away at the puzzle of the Nikumaroro sextant box I’ve learned that Brandis made several different types of sextants around the time that the hypothetical sextant with Brandis serial number 3500 and U.S. Naval Observatory number 1542 would have been manufactured.  This is the first of several posts about these different sextant types.  I’ll start by discussing Brandis surveying sextants.

Brandis Catalogue No. 20, which was published sometime between 1915 and 1917[1], lists as item number 105 a ‘U.S. Navy Surveying Sextant’, having a radius of 6 inches and providing a measurement precision of 30 arc-seconds.



Like all other Brandis sextants made at this time, U.S. Navy surveying sextants were vernier sextants.  A vernier sextant has an vernier scale on its index arm that allows users to read the sextant’s arc scale to a high precision.  Brandis Catalog No. 20 tells us that the vernier scale of its U.S. Navy Surveying Sextant allowed users to read the arc scale to a precision of 30 arc-seconds.  The two-headed screw that can be seen at the end of the index arm is an adjustment screw commonly referred to as tangent screw.  A user determining the angle of a celestial body above the horizon [2] first moves the index arm by hand until the celestial body’s image, as viewed though the sextant’s telescope, is approximately on the horizon.  The user then anchors the index arm to the sextant’s limb with a clamp that is connected to the index arm via the tangent screw (this clamp can’t be seen in the catalog illustration).  Once the clamp has been anchored to the limb, the position of the index arm is finely adjusted by turning the tangent screw to properly align the celestial body’s image with the horizon.  Bill Morris’ book The Nautical Sextant describes the Brandis index arm adjustment mechanism more clearly than I have here and provides photos of all the critical components.

 In ‘What do the Numbers 3500 and 1542 Tell Us? Part Three’, we saw evidence that Brandis made some 2400 sextants Brandis for the U.S. Navy during World War I, and that at least 1000 of them were surveying sextants.  Based on how frequently surveying sextants appear among surviving examples of Brandis sextants I’ve seen [2], my guess is that the Brandis made closer to twice that number of surveying sextants for the Navy during the war.  I should say that while I've seen many Brandis sextants that look to be a match for the surveying sextant featured in Brandis Catalog No. 20, I've seen one or two sextants that have some, but not all, the features of such a surveying sextant.  I'll leave discussion of these 'outliers' to a later post.

Comments, corrections, additional relevant facts, differing viewpoints, etc., are always welcome (no one will be banned, blocked, or castigated for offering differing opinions).  Send correspondance to gardnersghost@gmail.com 
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[1] Brandis Catalogue No. 20 is undated, however is contains a testimonial letter from a customer dated December 12, 1914, so the earliest it could have been published was some time in 1915.  The firm name on the front page is ‘Brandis & Sons Mfg. Co.’; in the post titled ‘What Do the Numbers 3500 and 1542 Mean? Part Three’ I concluded that that some time in 1917 the firm name changed to ‘Brandis & Sons, Inc.’.  Therefore, I think Brandis Catalogue No. 20  must have been printed some time between 1915 and 1917.
[2] I believe the ‘angle above the horizon’ of a celestial body should probably be called its ‘altitude’, but I’ll stick with the landlubber’s angle here and elesewhere.
[3] When I try to identify a Brandis sextant’s type, things I look for are its frame pattern, whether there is an U.S.N.O. inspection certificate stating its type, and how its arc and vernier scales are divided. 

Tuesday, October 6, 2015

The One That Got Away

A few months ago, I came upon an interesting Brandis sextant on an online auction web site.  Alas, I was unable to participate in the auction except to put in a bid a day or so before it was held, and my bid was bested by a small sum by the only other bidder who apparently took an interest in this item.  So, I lost my chance to own a sextant that I think has a particularly interesting history.

I noticed when I saw the lead photo in the auction catalog (see below) that this was not just another Brandis nautical sextant, it was a Byrd sextant.  Byrd sextants were one of the first types of sextants specifically devised for aerial navigation.  The leveling device was a spirit tube mounted to the frame beyond the horizon glass.  It was the spirit level, and a wire leading from it to the sextant’s handle (the spirit level could be illuminated at night by a small light bulb that was powered by battery in the sextant’s handle), that led me to recognize what I was looking at.  A Byrd sextant was aboard the NC-4, the U.S. Navy Curtiss seaplane that made the first-ever flight across the Atlantic Ocean in 1919.  But by the mid-1920s, the Byrd sextant had been replaced by other types of bubble sextants.



I know of only a few other surviving examples of Byrd sextants, all of them built on Brandis nautical sextant frames.  One example, Brandis #5296/USNO #2977, is at the Smithsonian Museum in Washington, D.C. [1]; this Byrd sextant flew on one of the Navy-Curtis seaplanes involved in the NC-4 transatlantic flight of 1919.  The Smithsonian’s web site says that this particular sextant was donated by P. V. H. Weems, the U. S. Navy officer who was one of the great pioneers of early air navigation methods and equipment [2].  A second Byrd sextant, Brandis #5292/USNO #2975, also flew on one of the NC seaplanes that attempted the 1919 transatlantic flight; it appeared on an auction web site several years ago and presumably is now in a private collection.  A third Byrd sextant, Brandis #4180/USNO #2859, belongs to Bill Morris, author of the excellent book The Nautical Sextant [3], and the equally excellent blog that complements the book [4].

Those are the only three surviving Byrd sextant I know of; quite possibly there are others, but I suspect not many others.  Just from the standpoint of its rarity, I thought this Byrd sextant was worth having.  But when I looked at the additional photos in the catalog listing, this sextant seemed even more interesting.  It has a micrometer scale rather than the tangent screw and vernier scale that is seen on the other three Byrd sextants; the clamping mechanism is also different (see below).  So I think this may be a somewhat later version of a Byrd sextant than the other three, the micrometer and clamp features intended to make it easier to use in flight.



One photo in the auction catalog shows that the sextant’s box has a Naval Observatory inspection certificate attached to it (see below).  The original Brandis serial number written on the certificate, 5996, is crossed out and written below it is the number 6006; photos of the frame of this sextant don’t show us which, if either, of these two numbers corresponds to its Brandis serial number.  More interesting is that the inspection certificate indicates the class of sextant to be “aeronautical”.  The inspection certificate for Brandis #5292, one of the Byrd sextants from the 1919 transatlantic flights, indicates it to be a “surveying sextant”, as do the inspection certificates of many U.S. Navy sextants that were used strictly for nautical purposes.  I think this lends support to the notion that this sextant was from the outset made for aeronautical navigation, not for maritime navigation.  Another interesting thing is that in the upper right hand corner of the inspection certificate is written “Weems 805W”.  I don't know what the “805W” refers to, but “Weems" must refer to the very PVH Weems whom I mentioned above.  It seems possible that this particular Byrd sextant was once in the possession of the great air navigation pioneer himself during that early period when he and others were working to advance the design of the aeronautical sextant.




In summary, while the three other Byrd sextants appear to be retrofitted Brandis nautical sextants taken from the run of 2400 sextants that Brandis produced for the U.S. Navy during the first World War [5], the Brandis Byrd sextant I failed to win at auction seems to be a somewhat later sextant specifically made for aeronautical use.  The Naval Observatory inspection certificate is dated October 8, 1920, so this provides a ‘no later than’ date for when Brandis #5996 was manufactured.  It seems likely that it was made some time after the Byrd sextants that flew on the May, 1919 NC transatlantic flights, so the date of manufacture of Brandis #5996 was probably some time between May, 1919 and October, 1920 [6], so it fits nicely into the Brandis serial number chronology I’ve been developing.

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 

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Footnotes and references
[1] http://amhistory.si.edu/navigation/object.cfm?recordnumber=451576
[2] http://timeandnavigation.si.edu/navigating-air/early-air-navigators/charles-lindbergh/business-of-air-navigation/p-v-h-weems
[3] The Nautical Sextant, W. J. Morris. Paradise Cay Publications, Inc. Arcata, California. 2010.
[4] http://sextantbook.com/?s=byrd
[5] See the earlier post titled 'What do the Numbers 3500 and 1542 Tell Us? Part Three'
[6]  The actual Brandis serial number of the sextant I bid on was more likely 6006 than 5996, but I think that date range likely applies to Brandis #6006 as well.

Thursday, August 27, 2015

A Fish Story

I haven’t posted in a while, and I think it may be a while yet before I make another long post.  In the meanwhile, a true story about the one that didn’t get away might be of interest to some in my vast readership.
 
An article that appeared in the January 1931 issue of Flying Magazine tells the story of a Long Island fisherman who discovered a sextant in his net while fishing halfway between Montauk Point and Block Island:


The fisherman, Arthur G. Wood, 94 Saxton Avenue, Sayville, L.I., took the sextant home with him, cleaned the corroded metal and read from the small plate:

            Brandis & Sons, Inc.
            Brooklyn, N.Y.
            6255
            Aeronautical Octant
            Mark 1    Model 2

The article goes on to say that the sextant was traced back to a U. S. Navy Lieutenant Schildhauer, who lost the sextant in 1928 when his U. S. Navy PN-12 flying boat was forced to land at sea due to engine trouble.

This fit-for-Ripley’s fish story is not only mildly entertaining, it provides us with another data point for the Brandis serial number chronology.  ‘Mark 1 Model 2 Brandis Aeronautical Octant’ is the name U.S. Navy gave to an early version of the Brandis Model 206 bubble sextant, which was introduced in 1925.  Therefore Lt. Schildhauer’s (or should we say Arthur Wood’s) Brandis #6255 sextant must have been made sometime between 1925 and 1928.

 At some point I will post an updated Brandis serial number chronology table that will include Brandis #6255 and perhaps some additional data points.

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 

Sunday, May 24, 2015

Some Old Brandis Surveying Instruments

The Brandis serial number chronology presented in the post ‘What do the Numbers 3500 and 1542 Tell Us? Part Two’ provides a pretty narrow range for the date of manufacture of the hypothetical Brandis #3500/USNO#1542 sextant, but it only sparsely covers the first decade of the 20th century.  This earlier period won’t help us date the Nikumaroro sextant box, but developing as complete a Brandis serial chronology is a good thing nonetheless.  Four time points for the 1900-1910 period can be established thanks to Robert Parrish of Antiquesurveying.com.  Robert’s impressive collection of surveying instruments includes six Brandis surveying instruments that can be dated in a very straightforward way: they are marked with the year in which they were manufactured.  The Brandis serial numbers and dates are listed in the table below.
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Instrument Brandis Number Date
Wye Level 2106 1905
Theodolite 2225 1906
Surveying 2290 1906
Theodolite 2309 1907

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In the photos below we can see how these markings appear on two instruments, a Wye level and a theodolite.


Photos Courtesy of Robert Parrish

Both instruments have the date-appropriate firm name of ‘F.E. Brandis, Sons & Co’, and both are marked “The President Borough of Richmond”, presumably their original owner (the ‘Borough of Richmond’ is very likely the part of New York City commonly called Staten Island).  The Wye level, Brandis #2106, is marked with the number 1905, while the theodolite, Brandis #2225, is marked with the number 1906; Robert thinks all of these markings were factory-engraved.  Can we be sure that the 1905 and 1906 are dates and not owner serial numbers?  I think we can, because another of Robert’s surveying instruments, Brandis #2290, is also marked 1906.  It’s not clear whether Brandis #2290 was also owned by the Borough of Richmond, but if it was, it would make little sense for it to be marked with the same owner’s serial number as Brandis #2225; if Brandis #2290 had a different owner then it would be quite a coincidence for it to have the same owner’s serial number as Brandis #2225.  I also note that 1905 and 1906 make sense as the years in which these instruments were made: they post-date the establishment of the Borough of Richmond in 1898 and they pre-date the 1911 delivery date of the sextant with Brandis serial number 2763 discussed in What do the Numbers 3500 and 1542 Tell Us? Part Two, as they should if lower Brandis serial numbers correspond to earlier manufacture dates.  Robert Parrish cautions that some instrument manufacturers assigned blocks of serial numbers to a single type of instrument or a single worker, which would tend to disrupt any order between manufacture date and manufacturer’s serial number; so far, I am not seeing signs of such discontinuities in the Brandis serial number chronology.

I’ll post an updated Brandis serial number chronology table that incorporates these surveying instruments, the Brandis #3249 peephole sextant, and any other datable Brandis instruments that might happen to come along; I’m hoping to get useful dating on one or two more Brandis instruments, so I may wait for a little while before updating the table.

Note added,  June 2018:  This post originally included information about two other Brandis instruments Robert Parrish provided date of manufacture information for, however I later realized these were not instruments owned by Mr. Parrish and will discuss them in a separate post.  Also, I should soon be publishing the long-promised revised Brandis serial number chronology table.

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  

Tuesday, May 5, 2015

A Strange Beast

While I’m not intending to make posts about every new Brandis instrument that turns up, a very interesting Brandis sextant and box appeared on eBay yesterday that I think is worth commenting about.  The sextant, Brandis #3249/USNO#836, is marked with the ‘Brandis & Sons, Mfg Co.’ firm name, and seems at first glance to be a common run-of-the-mill Brandis surveying sextant.  I noticed that the sextant didn’t have a telescope, but it’s not so unusual for sextant components to go missing from sextant boxes over the decades.  I also noticed that the sextant box was marked with the later ‘Brandis & Sons, Inc’ firm name marking, but a number of sextants that have turned up for sale are no longer in their original boxes, so that didn’t seem so unusual, either.  Then, taking a closer look at the photos of the sextant in the box, I realized this sextant wasn’t your average Brandis surveying sextant.  It wasn’t missing its telescope—it probably never had one.  Where a telescope would normally be attached there was instead an odd, two-wheeled contraption. 











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  


Thursday, April 30, 2015

What do the Numbers 3500 and 1542 Tell Us? Part Three

The Brandis serial number chronology presented in the last post indicates that there was a rapid increase in the production of Brandis instruments between 1917 and 1919: Brandis produced about 1134 instruments between 1900 and 1915, an average of about 76 per year, while it produced over 2000 instruments between 1917 and 1919, more than 1000 instruments per year.  In this post, I’ll present several additional sources of information that corroborate the timing and magnitude of this increase in production of Brandis instruments and link it to the United States’ entry into World War I in 1917.  These sources also help to narrow the date range over which the hypothetical Brandis#3500/USNO#1542 sextant would have been made, and provide evidence that Brandis assigned its serial number 3500 to a sextant rather than to any other kind of precision instrument it manufactured.

The first source of information we’ll look at are the annual reports of the U.S. Naval Observatory, which typically reported the number of new sextants inspected during the year (1).  The Naval Observatory’s annual reports were written on a fiscal year basis, which at this time began on July 1 of the calendar year, e.g., the Naval Observatory’s annual report for fiscal year 1916 covers the period from July 1, 1915 to June 30, 1916.  In the table below, I’ve compiled the Naval Observatory sextant inspection data for fiscal years 1916 through 1922; a caveat is that the annual report for fiscal year 1918 gives the only total number of sextants inspected, new and old, so it is not clear how many of the 818 sextants inspected in this period were new ones.  I will assume here that all the sextants inspected in fiscal year 1918 were new sextants; while that may not be precisely correct, I think information that will be presented later suggests that a large majority of them were in fact new sextants.



We can see that there was a rapid increase in the number of new sextants inspected at the Naval Observatory that coincided with the rapid increase in the production of Brandis instruments between 1917 and 1919 indicated by the Brandis serial number chronology.  Not all of these sextants could have been made by Brandis; we know that the instrument manufacturers Keuffel & Esser and Buff & Buff also supplied sextants to the U.S. Navy during this period because about a quarter of the World War I era Naval Observatory-inspected sextants on Tighar’s sextant number list (2) were made by these two companies.  However, the preponderance of Brandis sextants on Tighar’s list suggests that Brandis was the largest supplier of sextants to the Navy during World War I, and therefore the trend seen in the USNO annual reports must to a significant degree reflect the trend in production of Brandis sextants.

Information appearing in three publications brings Brandis’ wartime work supplying sextants to the U.S. Navy into sharper focus.  The trade journal Jewelers’ Circular-Weekly in its October 10, 1917 (3) contains a brief notice stating:  “An award has also been made to Brandis & Sons Co. of Brooklyn for furnishing 1,000 surveying sextants at $98,250”.  This would seem to be the contract that initiated Brandis’ wartime production of sextants, and if what is reported in Jewelers’ Circular-Weekly was fairly recent news, then production of sextants by Brandis for the Navy began no earlier than October, 1917.  I note that this article appears to have imprecisely stated the Brandis firm name, and so here we’ve missed an opportunity to better define the date of the firm name transition from the ‘Brandis & Sons Mfg. Co.’ to ‘Brandis & Sons, Inc.’, which is an important element in the Brandis serial number chronology.

Jewelers' Circular-Weekly, October 10, 1917

The Brandis advertisement in the December, 1919 issue of The Rudder, which was mentioned in the previous post, provides additional details about Brandis’ activities during the period in question.  Here it is stated: “Each sextant has our guarantee to pass inspection at the U.S. Naval Observatory as did the 2400 furnished by us to the US Navy Department during the period of the war”.  The key things we learn here are that Brandis produced a total of 2400 sextants for the Navy during the war, and that Brandis finished manufacturing these 2400 sextants before December of 1919, by which time it was once again making sextants for the civilian market (hence the need for an advertisement in The Rudder).

Finally, a publication called The Marine Review, in its February, 1920 issue (4), contains a brief piece that I suspect relies heavily on information provided by Brandis.  The third paragraph of this article provides several relevant pieces of information:

 “The company draws attention to the fact that its entire plant was devoted to the manufacture of sextants during the war, the whole output going to the United States Navy.  Prior to the war, the output of American made sextants never exceeded 200 yearly.  With the entrance of the United States into the war and the resulting upbuilding of an American Merchant Marine, sextant manufacturers expanded their facilities to meet the increased demand.  In less than two years, the Brandis company delivered 2400 sextants to the United States Navy”. 

Here again is the statement that Brandis produced a total of 2400 sextants for the U.S. Navy during the war, and we are also told that Brandis completed this work in less than two years, a time interval which is consistent with what the previous two sources suggest, that production of sextants for the Navy started no earlier than October of 1917, and was completed before December, 1919.

Marine Review, February, 1920

The Marine Review also tells us that the only type of instrument Brandis manufactured while fulfilling its Navy contracts were sextants, all of which went to the Navy.  This implies that the Brandis serial number series should have increased by about 2400 between 1917 and 1919, and that all of the Brandis sextants made during this period were marked with Naval Observatory serial numbers.  This is pretty much what we see in the Brandis serial number chronology: Brandis was making sextants with serial numbers in the 3200-3300 range in 1917, and sextants with Brandis serial numbers in the 5600-5700 range could well have been made in 1919.  Additionally, an examination of the Tighar sextant number list reveals that all of the 48 Brandis sextants with serial numbers from 3243 to 5628 do in fact have Naval Observatory numbers (5,6). 

It isn’t possible with the available information to give precise serial numbers or dates for the beginning or end of Brandis’s production of the 2400 sextants for the Navy, and while the Marine Review article indicates that during the war Brandis’s entire factory was dedicated to producing sextants for the Navy, it appears that there wasn’t a sharp transition from making sextants for the Navy to making instruments for other customers at the end this production period.  This can be seen in the table below, which indicates the Naval Observatory serial numbers (if any) of the sextants with the five highest Brandis serial numbers of any that have come to light.  The second sextant listed, Brandis #5687, does not have a Naval Observatory serial number, while the next two sextants, Brandis #5760 and Brandis #5851, do have Naval Observatory numbers.  If the Naval Observatory serial number of the latter two sextants were higher than any made before them, one might reasonably think that they were produced after the war under a separate postwar Navy contract.  But Brandis #5851 has a Naval Observatory serial number 1110, which is lower than all but a few of the Brandis sextants on Tighar’s sextant list, thus it is reasonable to assume that this sextant was part of the wartime run of 2400 sextants made for the Navy.  We should probably also consider it possible that the outset of Brandis’ work for the Navy did not involve a distinct transition from civilian to Navy work.


The information provided by these various publications nicely jibes with the timing and magnitude of the increase in the production of Brandis instruments indicated by Brandis serial number chronology over the 1917-1919 period, and so provides independent corroboration of the accuracy of this portion of the Brandis serial number chronology. 

This additional information is also helpful in somewhat narrowing the estimated date of manufacture of the hypothetical Brandis #3500/USNO#1542 sextant.  As discussed in the previous post, the sextant with Brandis serial number 3243 is marked ‘Brandis & Sons Mfg. Co.’, while the sextant with Brandis serial number 3331 is marked ‘Brandis & Sons, Inc.’  Since this firm name change occurred sometime between July and December of 1917, some or all of the instruments with Brandis serial numbers between 3243 and 3331 must have been made in the second half of 1917.  Brandis was awarded its first contract to produce sextants for the Navy before October 10, 1917; the sextant with Brandis serial number 3243 doesn’t have a Naval Observatory serial number, and thus was made either before Brandis began producing sextants for this contract, or before Brandis dedicated its entire manufacturing capacity to producing sextants for the U.S. Navy.  The sextant with Brandis serial number 3331 does have a Naval Observatory serial number (USNO #1421), and would have been made early in Brandis’s production run of 2400 sextants for the Navy.  I think it is reasonable to assume that Brandis started dedicated production of those 2400 sextants no more than two or three months after the first contract award, and given that Brandis produced an average of 200 sextants per month while fulfilling its Navy contracts, it seems reasonable to think that the hypothetical Brandis #3500/USNO #1542 sextant was made within a month or two of the start of dedicated production of sextants for the Navy.  Thus, I think the most likely date of manufacture of this sextant would have been between one and five months of the award of its first Navy contract, i.e., sometime between November, 1917 and March, 1918.

The sextant with Brandis serial number 3331 would seem to be one of the early sextants made for the Navy’s first order of 1000 sextants.  Given the relatively low rate of production of instruments by Brandis prior to the war, it seems likely that by the time Brandis issued serial number 3500, its manufacturing plant had reached the point of dedicated production of sextants for the Navy.  Thus, besides leading to a somewhat narrow date range for the manufacture of the hypothetical Brandis #3500/USNO#1542 sextant, the information presented tells us that Brandis serial number 3500 was probably issued to a sextant rather than any other type of instrument Brandis manufactured, such as a surveyor’s level.  In this post and in others, I’ve referred to ‘the hypothetical Brandis #3500/USNO #1542 sextant’, but it seems likely that Brandis serial number 3500 was assigned to a sextant, so what unclear is whether the Naval Observatory assigned their serial number 1542 to the Brandis #3500 sextant. 

Readers may have expected me to also present a Naval Observatory serial number chronology to complement the Brandis serial chronology.  It would be nice to have this additional dating tool, but developing a Naval Observatory serial number chronology would seem to be a difficult endeavor.  One might construct such a chronology by searching for Naval Observatory inspection certificates with pre-World War I inspection dates, but no such inspection certificates have yet come to light, and I think the chances of finding any are fairly slim.  Judging by Tighar’s sextant number list, there are few pre-World War I U.S. Navy sextants to be found; this is probably because the Navy did not purchase sextants in large numbers prior to World War I (7).  Sextants were often re-inspected at the Naval Observatory once in service (8), and therefore if and when additional pre-war Navy sextant boxes come to light, there is a good chance that the inspection certificates they contain, if any, will indicate the dates of later re-inspections; I say ‘if any’ because it isn’t unusual for the inspection certificates to be missing from Navy sextant boxes of this era.  Also, while the research I’ve done so far indicates that the Naval Observatory started using serial numbers in the 1880s, I am not sure that the Naval Observatory serial numbers were consistently assigned to sextants prior to World War I; but this is subject that I’ll leave for another post.

Finally, many familiar with Tighar’s sextant number list have commented on the absence of an obvious relationship between Brandis and Naval Observatory serial numbers.  The absence of a correlation between these two sets of serial numbers suggests that the Naval Observatory made no effort to inspect sextants and assign Naval Observatory serial numbers to them in order of their manufacturer’s serial number, at least not during the 1917-1919 period.  I speculate that at this time the Naval Observatory’s storage area for sextants often contained many hundreds of newly-manufactured, yet-to-be-inspected,  Brandis, Keuffel & Esser, and Huff & Huff sextants, which were not carefully stored with regard to manufacturer’s serial number; batches of sextants would be retrieved from storage for inspection based on accessibility rather than with regard to manufacturer’s serial number (or even manufacturer), thus precluding a predictable relationship between sextant manufacturer serial numbers and Naval Observatory serial numbers.  An additional factor contributing to the lack of a correlation is that while the bulk of the Naval Observatory’s serial numbers appear to have been assigned to sextants, at least some Naval Observatory serial numbers were assigned to  instruments besides sextants, for instance timepieces, which also tended to reduce the correlation between Naval Observatory and manufacturer’s serial numbers.  More can be said about the subject of Naval Observatory serial numbers, but this is perhaps should be discussed another time.

Comments, corrections, additional relevant facts, differing viewpoints, etc., are always welcome (no one will be banned, blocked, or castigated for offering differing opinions).  Send to gardnersghost@gmail.com 
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 Footnotes
(1) USNO Annual Reports can be downloaded at hathitrust.org.  Sextants were inspected prior to going into Navy service, and the term ‘new sextant’ in this context refers to sextants receiving their first inspection at the Naval Observatory; many, if not most, sextants were re-inspected once in service; see footnote 8.
(2) http://tighar.org/wiki/Sextant_box_found_on_Nikumaroro
(3) The Jewelers’ Circular-Weekly, Volume 75, Issue 1, page 59.  Jewelers’ Circular Publishing Co., October 10, 1917.  This can be found online at Google Books.
(4) Marine Review, Volume 50,  February, 1920, page 127.  Penton Publishing Company.  This can be found online at Google Books.
(5) The sextant with Brandis serial number 3243 seems to have been inadvertently left off the Tighar sextant number list, or deleted from it.
(6) In addition these 48 sextants, the Tighar sextant number list includes five Brandis sextants whose serial numbers are known only from markings on their sextant boxes; since the Naval Observatory didn’t consistently mark boxes of inspected sextants with USNO serial numbers, it is not known whether the sextants these five boxes once stored were had USNO serial numbers.  Tighar lists a sixth sextant in this range, Brandis #3702, as having no USNO serial number, but the discussion here: http://tighar.org/smf/index.php/topic,183.msg1696/topicseen.html#msg1696  indicates that this sextant has an illegible USNO serial number.
 (7) Only 25 new sextants were inspected at the Naval Observatory in each of fiscal years 1916 and 1917; several earlier USNO Annual Reports I have had access to indicate similarly small numbers of new sextants inspected or purchased.  Note also that the Marine Review article states “Prior to the war, the output of American made sextants never exceeded 200 yearly”; presumably many of these “200 yearly” sextants were sold to civilian customers rather than to the U.S. Navy.
(8)  This can be seen by the many examples of U.S. Navy sextant boxes on the Tighar sextant number list containing inspection certificates that are dated many years after Brandis’ demise; also, sextant boxes containing two differently dated inspection certificates have come to light.