Abstract: An apparatus of and a method for the construction of an environmentally-friendly floating dock structure using heavy-gauge plastic tubing as pontoon floats with an overlying series of deck crosspieces is presented. The plastic pontoon floats are made from a high-density polyethylene material and arranged with the overlying deck crosspieces in such a manner as to provide the floating dock with a greater degree of stability, and are themselves constructed containing a highly buoyant material. The junctures between the adjoining pieces of the pontoon floats are sealed water-tight by a plastic joining process.

Abstract: An apparatus detects a magnetic tag implanted in an organism as detector is moved past the organism by detecting a magnetic field difference between two positions. Prior to examination of a specimen under test, the outputs of a plurality of loops detecting magnetic fields are balanced in a uniform magnetic field. As a consequence, when one of the coils is exposed to a different magnetic field than the other of the coils this difference is detected and an alarm is sounded to indicate that the magnetic tag has been detected.