2. Range Board.—Show how to make the range corrections for atmosphere, wind, tide, muzzle velocity, travel, and how this range correction is applied to the range-correction scale.
3. Deflection Board.—Show how to make deflection correction for wind, drift, and travel. Show how to make azimuth correction in Case 3 for wind, drift, travel, and how this correction is applied to azimuth correction scale.
What data are sent to the guns in Case 1, Case 2, and Case 3?
The plotting-room (for mortars).
1. Plotting-board.—Point out the following: Primary and secondary stations, directing point, gun-arm, gun-arm azimuth circle, displacement, powder zones, elevation, times of flight.
Lay off a distance of so many yards on the board; conversely tell the distance between two given points on the board.
The range and azimuth of a fixed point (from primary station) being given, locate the corresponding point on the board. Tell the zone, elevation for firing at this point, and its azimuth from the directing point. The azimuth of a fixed target from the primary and secondary stations being given, locate the corresponding point on the board and determine its range and azimuth from the directing point.
2. Show how a target is tracked, how to get travel, how the time of flight is used, how to get predicted point, how to get set-forward point. What is the predicted point used for? What is the set-forward point used for? What data are sent to the pit and what to the B. C. station? Show how range corrections are made.
3. Drift Device (for deflection board if issued).—Show how to make arbitrary and drift corrections.