288,767. Newton, P. I. Feb. 11, 1927. Teaching gunnery and ranging.-In a miniature range for gunnery instruction, means are provided for introducing a ratio of movement between the lines gun-target and sight-target, so that for any movement of the target towards or away from the gun there will be a change of tangent elevation which will have to be taken up by altering the range on the range dial. This is obtained by means of a pair of mirrors k, l. Fig. 10, one k above the line from the gun G to the target T, the other l below that line. The sighting is done by reflection from these mirrors, and the setting of these mirrors determines the aforesaid ratio of movement. The gun G and the mirrors k, l may be mounted on a circular base as shown in Figs. 5, 6; and a device p may be provided to change the pointing of the gun and to make the same gun simulate various guns of a battery. The target shown in Figs. 1, 2 comprises a wooden framework a covered with a layer of sand or sawdust b forming a concave sloping surface, over which one or more tanks d or other targets of rubber or wood are moved by means of cords e. A stop butt c is fitted behind the target and may be camouflaged with background and sky.