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1) The earliest aircraft sextant I have is a Brandis Aeronautical
sextant Mark I, Model 4., dating from 1931. Its form is that of a
small nautical sextant of radius 125 mm, but, sensibly, it has legs on
the front so it can be placed face downwards. It has the usual shades
and also has a battery handle so that the scales can be illuminated
with a tiny lamp. This handle also provides power to light the bubble
cell, from above, of a Willson telescope. The sextant is also provided
with a sighting tube.

The box is of mahogany, with box-comb corner joints and solid base and
lid. It differs from normal sextant cases in having a separate sliding
lid, secured by two hooks and eyes and a drawer lock. Let me know if
you would like photographs.

The UK Mark IX series of aircraft sextants had from the start cases
made of a phenolic resin plastic, held together with brass screws and
nails, though occasionally they are found in sheet aluminium cases.
Hughes and Son also made "Flying Boat" sextants, which were
essentially nautical micrometer sextants of reduced size, used for
taking anchor bearings. These too were made of the same type of
plastic, but were of standard shape, with interesting circular latches
of a type previously seen only on the wooden boxes of their top-of-the-
line nautical sextant.

The US aircraft sextants showed as much variety in their boxes as in
their design. I can go into this if you like, but I understand your
question to be about early aircraft sextants of traditional form.

2. Perhaps the best person to answer your second question is Ian
Paine, who has corresponded extensively with WWII RAF navigators and
made many dry land observations with Mark IX series sextants. I will
alert him to your enquiry. For my part, I find the Brandis sextant
rather difficult to use on dry land, so can only imagine what it must
have been like to use in the air.

On Nov 16, 9:31�am, "Jackie Ferrari"  wrote:
> Dear Listers,
>
> I have two questions that I am hoping someone might be able to answer.
>
> I understand mariners' sextants �were sometimes carried in aeroplanes in 
addition to octants, in the early days of aerial navigation.
>
> 1. Were their boxes modified ie made of aluminium perhaps ?
>
> 2. How much use were sextants in the air?
>
> Thanks,
>
> Jackie Ferrari
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