Sunday, May 28, 2017

Learning the Sextant

Captain W.D. Puleston, U.S. Navy.  Annapolis.  Gangway to the Quarterdeck.  Appleton-Century Company, 1942.

"Youngsters"?  How quaint!
Maxim Newmark.  Illustrated Technical Dictionary.  New York:  The Philosophical Library, 1944.
Funk & Wagnalls New Practical Standard Dictionary.  Britannica World Language Edition.  1946, 1957.

Interestingly, according to a 2016 CBC article, the Royal Canadian Navy continues to train sailors in the use of sextants as a back-up to GPS. The U.S. Navy had discontinued this instrument, but only recently brought it back as a precaution against cyber attacks which might render a ship's GPS unusable.  According to the CBC article:
All watchkeepers and navigators on a ship are required to be proficient with a sextant, and they are required to practise sextant use while at sea at least once every 180 days.
"It's a skill set that if you let erode, it's very hard to get back because it's not an easy piece of equipment to use or train on," O'Regan said.
"Once you get good at it offshore, you can get within a nautical mile of where the ship actually is."
O'Regan says that when sailors first get their hands on a sextant, they usually think the gadgets are "pretty cool," and O'Regan agrees.
"It sort of makes you part of a navigational community that we're still using the same skillset that the sailors in Captain Cook's age would have used," he said. "There's parts of Canada where Captain Cook and various other hydrographers and cartographers have used sextants to develop those charts. It makes you part of a big club."


João Custódio said...

It seems that both sextant pictures are of geodesic sextants (to use inland, in an horizontal plane, therefore the three legs), as nautical sextants are held vertically.
In this age, There are 5 active good sextant manufacturers (plus a chinese one).

Cassens & Plath
Bremerhaven, Germany

Freiberg Präzisionsmechanik
Freiberg, Germany

State Research Center of the Russian Federation
Saint Petersburg, Russia

Tamaya & Company Limited
Tokyo, Japan

Davis Instruments Corp.
Hayward, California

The Duke said...

Thanks for the additional information! I wonder how many manufacturers there were back in the 1940's? More than five, I'd expect.

João Custódio said...

I've checked the net, none from Canada though:
(below list before 1950, taken from:

J. Hicks
London, England

London, England

G. W. Heath
London, England

Henry Hughes
London, England

Francis Barker & Son
England (where?)

East Berks Boat Co. (EBBCO)
Berkshire, England

London, England


Toizaki and Company
Shi Chiba-Ken, Japan

Asahi Optical
Tokyo, Japan

Keuffel & Esser
New York, New York

Bausch & Lomb Optical, Co.
Rochester, New York

Binghamton, New York

Fairchild Camera and Instruments Corporation
New York, New York

Link Aviation Devices
Binghamton, New York

David White Co.
Milwaukee, Wisconsin

Pioneer Instrument Company
Brooklyn, New York

Bendix Aviation, Pioneer Instrument Division
Bendix, New Jersey

Kollsman Instrument Corporation
Elmhurst, New York

Mergenthaler Linotype Company
Brooklyn, New York

The Duke said...

Well, while sextants are a lot more complex than buggy whips, the economics are the same. As demand drops, it gets to a point where it's no longer profitable to make them.

João Custódio said...

And as with buggy whips, there's a relatively small although strong market. Besides being a beautiful precision equipment, there's a certain need from anyone who ventures into high waters as even those who rely solely on GPS fells somewhat more comfortable on having one aboard. Even airmen, there are stories of airmen getting out of very bad navigational situations by using one.