SHORT NOTES ON THE 13-PR. M.L. GUN. 
165 
FitzEoy^s deflectors are fitted to tlie guns of cc A.” Batt., “ A” Bde., 
E.H.A., and add materially to tlie excellence of practice. When firing, 
however, at even ordinary ranges, on by no means exceptionally bad 
ground, it was often found that the amount of correction to be given 
on the deflection scale was over 30', the length to which it is graduated. 
Much time was constantly lost in levelling the wheels when this was 
the case. 
A line is cut to show where base of shell should rest when home, Marks, 
and another the end of the bore. 
In consequence of the length of the gun, it is always necessary, Elevating 
before limbering-up, to run the elevating gear down till the breech gear * 
rests on the upper transom of the carriage: 
The system adopted gives great quickness, in order to avoid loss of 
time. It consists of an arc attached to the cascable of the gun, 
having teeth cut in the rear edge, geared into a pinion on the same 
shaft with a worm-wheel fitted into a friction cone. The worm- 
wheel is geared on its shaft by a friction cone, adjusted by a nut 
and keep-nut outside the covering; the object being to allow a slight 
slip when the gun is fired, while there is at the same time sufficient 
friction to admit of elevation and depression being given. From 
various causes the friction cones have to be constantly adjusted, and 
it is as well to have the spanner always ready for the nuts. 
The play which it has been found necessary to give between the 
different parts of the elevating gear, in order to prevent jamming, is, 
as in our other systems, a fruitful source of error in range. As the 
reason for this is not very generally known, it may be briefly explained 
here. To support the breech firmly it is necessary that the upper 
surface of the cascable-pin should be in contact with the cascable, the 
lower surface of the elevating arc with the upper of the worm. The 
exact contrary is the case if elevation is the last motion given; and the 
lowering of the tangent scale and inserting the friction tube is sufficient 
to force the breech down. The resulting errors of elevation were 
found in some 16-pr. and 9-pr. M.L. guns which had been some time 
in use to be as much as 10', and in one case 13'. In some of the 
13-prs. it is as much as 10' at the present time, and will doubtless 
increase. This at short ranges would give 90 yds. error. The simple 
precaution is always to end with depression, or to bring the supporting 
surfaces into contact by gently reversing the wheel until there is a 
slight pressure against the hand, when ending with elevation. 
A self-acting rachet brake is attached to the rear flange of each Brake, 
gun-wheel. This is used only when firing; in travelling the pawl is 
secured out of gear by a sliding collar on the guard-iron. The 
brake-band is kept in adjustment by tightening the screw, and is 
held during recoil by the self-acting pawl. The band should exert 
as much frictional resistance as possible, without actually skidding the 
wheels; a “ tommy ” for its adjustment is carried under the back of 
the near axletree-seat. During firing it requires constant attention, and 
the drag-shoe will often be found more certain and less troublesome. 
The handspike will, in all probability, be altered, as it is not a Handspike, 
success. It need not, therefore, be described. 
