Abstract: A refrigerant precooler device, connecting into the Freon line of an existing air conditioning unit, and directing this freon through a finned cooling coil, and having a downdraft fan blowing air downward onto a supply of water in the bottom of the precooler device, and the fan blades being surrounded at a strategic location by a venturi shroud, which tends to disperse some of the air from the fan outward, and over the fins of the cooling coil, thereby causing an accelerated evaporation effect, with the added cooling of the Freon. A controlled supply of water in a reservoir at the bottom of the device is pumped upwards through a tubing device and into a pipe which is located onto the top of the cooling coil, and the pipe has a slot cut lengthwise of its bottom longitudinal dimension, and the pumped water drips out of the slot in the pipe, and drains downward over the fins of the cooling coil.

Abstract: A control system for a magentic submarine mine adapted to be fired automaally upon the approach of a vessel and in which the possibility of premature detonation of the mine by a minesweeper is substantially reduced. For example, some of the magnetic mines being laid in a particular mine field may be set so that after several actuations by a minesweeper a few of the mines will be exploded, the remaining mine field requiring a larger number of signals before detonation. By varying the number of signals before a mine is detonated the particular mine field after being swept is still considered lethal because many of the mines are left in the armed condition and others awaiting to be armed by subsequent minesweeping or the passage of vessels, as the case may be.