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Apparently provides a rapid graphical solution for mathematical problems that were
difficult to solve in a timely manner without a computer.

I have also seen the three-arm protractors (station keepers) on ebay relatively often
and think about how these could be replaced with a computer program.  Two
bearings are taken on three  land-based objects resulting in a fix.  Anyone know of a
mathematical solution?

Frank
Rochester, NY



Date sent:              Sun, 5 Mar 2006 13:13:17 -0800
Send reply to:          Navigation Mailing List 
From:                   Paul Hirose 
Subject:                Battenberg Course Indicator
To:                     NAVIGATION-L@LISTSERV.WEBKAHUNA.COM

I came across this by chance while prowling the Internet. "The
Battenberg Course Indicator was invented in 1892 by Captain H. S. H.
Prince Louis of Battenberg, G.C.B., afterwards Admiral-of-the-Fleet
The Marquess of Milford Haven, P.C., G.C.B., G.C.V.O., K.C.M.G., LL.D.
It is practically the mooring board in mechanical form, and is
designed for the rapid solution of a series of ordinary speed and
distance triangles frequently met with in fleet work."

To me the instrument looks like a mechanization of the maneuvering
board. It has arms and sliders on which you set up the inputs and read
the outputs. "Owing to the small inaccuracies inseparable from an
instrument built with moving parts on robust lines, the answers
furnished by individual instruments will vary slightly."

http://www.gwpda.org/naval/ou5274.htm
(This consists of scans of the instructions, and photos showing the
setups for several example problems. It must total a couple meg, so
there will be a delay with a dial-up connection.)

There are several other interesting links at the parent site. "Boxing
the compass, points of the compass", etc.

http://www.gwpda.org/naval/n0000000.htm#swt

I found the 1908 document "Coaling from a Collier" interesting, though
the instructions were about 70% incomprehensible due to the thicket of
terminology. Good grief, what a detestable task coaling must have
been! "The first maxim in coaling should be to get every single
officer and man that can be spared, into the collier to dig out the
coal... You will find at the commencement of a commission, that there
are various ratings who look upon it as a right to be excused coaling.
Meet them with a stony eye, and say there is no such thing as 'having
a right' when the coal has to come in."

The author, Christopher Cradock, commanded the small British force
that confronted von Spee's powerful squadron in the battle off Coronel
in 1914. He was killed when his cruiser HMS Good Hope blew up.

   

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