Abstract: A vibratory seismic surface source includes a single vibrating mass, the energy of which is coupled with the earth through a ground contacting base plate. The vibrating mass is connected to the base plate by means of a ball and socket joint which constitutes a universal pivot for the vibratory axis of the mass. Thus, this vibratory axis may be made to assume any vector path with respect to a seismic line. In this manner, any desired combination of compressional and shear waves, both SH and V type, may be generated and recorded simultaneously at a point on the earth's surface remote from the source.

Abstract: Improved gun-firing system for electrically augmenting the energy released y ignited propellant of the system so as to increase the velocity of the projectile as it launches from the system thereby increasing the probability that it will strike a fast-moving target. The system is generally made up of a barrel and a breech. The breech is provided with a firing chamber for receiving a projectile and an ignitable propellant. In one embodiment, the breech of the system is generally comprised of a detonator, a pair of relatively spaced pressure-responsive switches and a helically wound electromagnetic coil. A power supply is connected by an interlock to the switches and coil such that the coil is not energized until both switches close. These switches close in response to the pressure of the plasma that has been progressively formed from igniting the propellant in the breech chamber.

Abstract: A recoilless electromagnetic projectile launcher is provided with a pair of projectile launching conductors, a source of high current, a sliding armature for conducting current between the conductors and propelling a projectile, and a structure which creates a force which is equal but opposite to a recoil force created as the projectile is accelerated. This structure includes a second pair of conductors for accelerating a recoil mass in a direction opposite to the direction of travel of the projectile or, alternatively, an expansion chamber and nozzle for accelerating hot gases resulting from the creation of a plasma armature, in a direction opposite to the direction of travel of the projectile.