Giving a series of electrical impulses at a predetermined spacing, a robot bombardier automatically releases bombs in any desired number and at any interval. Just invented, the machine takes into account the ground speed of the airplane, and it is connected simply by plugs so that it can be removed from one plane and installed in another. The time control is by motor, which is connected to a dial indicating the intervals between bombs on a series of concentric circles corresponding to different ground speeds. The aviator adjusts the motor until the hand points to the desired interval for dropping bombs at the correct ground speed. Then he sets another dial for the number of bombs. Another instrument patented recently by a Czecho-Slovakian inventor measures the speed of an approaching airplane. The observer sights through the instrument, counts the seconds elapsing while the plane passes between two points on a horizontal index; then the observer plots the altitude - found by another instrument - on the dial and reads the plane’s speed.