a1 (Ministry of Supply)
Amongst the schemes for simplifying the processes of astronomical position fixing the family of multi-star sextants contains some interesting material. By the simultaneous observation of two or more stars through an optical system coupled to a gravity reference, it is possible to determine the observer's position directly in latitude and longitude, with little or no computation.
The number of instruments on these lines which have been designed is very large and it would not be possible to describe them in detail in the course of a short paper. A few remarks about their principles may, however, be of interest since they are, in general, sound in theory and fall short of practical requirements only because, when used on an unstable platform such as a ship or aircraft, they make too heavy a demand on the skill of the observer.