Method of obtaining a variable movement of a miniature target,
corresponding to rolls of a vessel of from 1 to 10 degrees. A series of
25,000 shots were fired thus, by eight gun pointers, at targets
corresponding to the size of a battleship as seen at ranges of 1,500,
3,000, 6,000 and 9,000 yards. Using a sub-caliber rifle rigidly attached
to the muzzle of the gun and fired electrically by the firing gear of
the big gun. The record shows that under circumstances of average
difficulty at sea (say 5 degrees roll and range of 3,500 yards), the
gain in accuracy (increase in hits with a given expenditure of
ammunition) is about 25 per cent, and the gain in speed of hitting
(number of hits in a given time) is 50 per cent, with the two-hand gear
as compared with the usual one-hand gear.
RANGE FINDER AND PREDICTOR; HOME AND DISTANT STATION INSTRUMENTS. (See
page 403.)
Continuous readings, by means of automatic indicators, of either the
actual or the predicted ranges and azimuths of moving target at every
instant and for any distance from 1,000 to 15,000 yards and through an
azimuth of 160 degrees, are clearly presented at all times. The ranges
are read in scales of 10-yard steps, and the azimuths for each .01
degree are traversed. The corrected ranges for the various guns served
by the instruments, either actual or automatically predicted for any
interval of time, are constantly communicated to the various guns whose
fire is being directed by the observation instrument.