428 THE (C LINING-PLANE 3) OP THE GERMAN FIELD 'ARTILLERY. 
vided with a notch at one end and a pointer at the other. It can be 
adjusted in any position by means of the clamping screw. 
Every gun carries a lining-plane in the trail-box. It is employed as 
follows : 
The Battery Commander designates one of the guns and selects a 
lateral auxiliary mark, plainly visible to the whole battery and not too 
near. The gun named is trailed into the approximate line of fire and 
the position of the wheels marked. The lining-plane is then placed 
upon the plane surface on the top of the breech, with its diameter co¬ 
inciding with the line cut on the gun at right angles to the axis of the 
bore. The gun-layer then directs the sighting arm on the auxiliary 
mark, clamps it, and reads off the number of degrees on the base-plate. 
This reading, say 40, is communicated to the Battery Commander, who 
then gives the command to the whole battery: LIUING-PLANE— 
EIGHT, CHURCH STEEPLE, 40. The lining-planes of the remain¬ 
ing guns are then set to the graduation ordered, placed upon the guns 
and the trails are thrown round until the sights of the sighting-arm 
are directed on the auxiliary mark. After the first rounds the line is 
corrected if necessary by altering the graduation (by order of the 
Battery Commander) and shifting the trails until the sights of the 
lining-plane are again laid on the auxiliary mark, the instrument being 
so constructed that each degree gives a lateral deviation of •jV of the 
range. 
Elevation is given by quadrant. 
When the line has been obtained, the battery ranged, and fire distri¬ 
buted, the lining-pickets are planted in rear of the guns, which are 
then lined on the pickets in the usual way. 
