Abstract: A cap having a writing surface attached to its crown. The writing surface is configured to erasably receive writing inscribed thereon by the wearer. There is also included at least one writing implement for inscribing the desired expression or design on the writing surface. The writing implement is removably attached to one of the sides of the cap. The cap also has an eraser for erasing the message from the writing surface when it is desired to partially or completely change the message being communicated. The eraser is also removably attached to one of the sides of the cap.

Abstract: A non-destructive and non-invasive method of detecting underground tank leaks using three phase testing. A plurality of boreholes are drilled around the tank with the boreholes preferably extending below the tank. In the first phase of testing gas vapor analyzer is used to determine which borehole contains volatile organic material. In the second phase, a neutron back scatter gauge is lowered into those boreholes indicating presence of volatile organic material, and readings are taken at intervals along the length of the borehole. All of the readings are correlated. A sharp increase in reading, over a base reading, detects a probable "leaking" organic material beyond that present in the ambient soil. The third phase of the testing is to identify the probably "leaking" organic material and confirm if it is the same as that contained in the underground tank.