Abstract: A screw having a threaded shaft, a head on the shaft and means to permit rotation of the screw. There is a longitudinal slot extending along at least a portion of the threaded shaft to receive a locking member. The invention has a particular application in a wood screw and the locking member is, preferably, a flat body having a sharpen tip. Using the invention a wood screw may be secured against vandalism.

Abstract: A system to install a vandal-resistant screw. The system includes a screw having a head with a peripheral thread on the head. A tightening member is formed with a cavity. An internal thread within the cavity is able to tighten onto the peripheral thread on the head of the screw. A finishing member is formed with a cavity adapted to fit over the screw head. There are abrading surfaces within the cavity of the finishing member whereby the thread on the periphery of an installed screw can be abraded away by the abrading surfaces.

Abstract: A shark trap including a float. A first line extends from the float. There is a hook on the distal end of the first line. A housing is provided on the first line, below the float. A second line is slidably received in the housing. The trap has a second and third hook, one on each end of the second line. A shark taking bait on a hook will be susceptible to attack by other sharks.

Abstract: Apparatus to split a body in which the apparatus is received. The apparatus has a first metal component of a first coefficient of expansion and a second metal component of a second coefficient of expansion, different from the first. The second body is attached to the first body. Whereby heating the apparatus causes a marked distortion in the apparatus to exert force on a body in which it is received, sufficient to split the body.