20 
A TELESCOPIC SIGHT FOR FIELD GUNS. 
BY 
LIEUT. D. E. DOWNING, K.A. 
The advisability of being able to lay even a field gun by means of a 
telescope with cross wires was first suggested to me at the annual 
practice of the battery by the impossibility of getting two men to lay 
two guns alike if left to themselves, and the consequent difficulty in 
obtaining the correct elevation by trial shots. Since then I have 
observed certain conditions in which the bios. 1 declared themselves 
unable to lay when the object was quite apparent through glasses. In 
the early morning, at tolerably long ranges, it is very difficult to lay 
correctly, and certain conditions of ground, especially favourable to 
your own position (such as a slight rise with grass on it, &c.), render 
objects sometimes almost invisible which are really not so. Gun-pits 
and entrenchments are, as is well known, very difficult to lay upon 
with the unaided eye. 
It seemed, therefore, to me that if a simple arrangement could be 
devised which would stand rough usage and at the same time retain 
its accuracy, it would prove a great boon in (1) ensuring greater 
accuracy of fire; (2) enabling you to fire under certain circumstances 
when you would otherwise have to move the battery to a fresh position 
or wait for a better light; and (3) relieving the strain on the eye in 
laying. _ 
The instrument I am about to describe was made by myself, with 
the aid of the battery artificers; it had naturally, therefore, to be 
constructed on principles that did not involve any very nice finish of 
workmanship. From my own experience of the working of it, I was 
thoroughly satisfied with the results; the principal alterations it 
required being those of simplification instead of elaboration. 
The material difficulties to be overcome in applying a telescope for 
use in laying a field gun are : — 
1. The means of attachment must be such that no difficulty may be 
experienced in taking it off and laying it on, the mechanism must not 
be liable to injury in such ordinary operations as mounting and dis¬ 
mounting the gun, and there must be no chance of the relative 
position of the telescope to the axis of the gun altering in the opera- 
tions of fixing and unfixing. 
