Abstract: A device for use in inserting soft and flexible tubular devices into a body passageways, said device characterized by being formed from a flexible base, such as multiple-strand nylon thread and having deposited upon said flexible base a soluble material such as gelatin, said soluble material characterized by being less flexible than said base in its undissolved state.

Abstract: A marine auto pilot employing a compass with a Hall-effect sensing element in conjunction with a magnetic circuit designed to provide a high intensity magnetic field; electrical circuitry designed to produce high servo-loop gain at frequencies lower than the normal sea wave frequencies, and lower gain at the normal sea wave frequencies; a D.C. Linear Motor drive system in conjunction with a rudder position feedback signal; and a linear ball-screw and nut gearing system for converting the high-speed output of the direct current drive motor to a low-speed high-torque drive at the rudder, having the nut and ball-screw connected through rolling contact balls.