Stearns

This case concerns a 'holiday detector. Holiday detectors are used in the installation of underground pipe. All pipe, regardless of its composition, is subject to ravages of time and the elements and must be replaced. Consequently, from the very beginning of the industry there have been sought ways and means to extend the life span of underground pipe. Within the past several decades steel has been used more and more for underground pipe lines, but steel is also subject to- corrosion and decay. To retard corrosion pipe was coated with a tar-like substance, applied by 'hand with a brush. However, hand coating was not perfect.

Holes in pipe coating are called “holidays” in the pipe industry, and a holiday detector is an apparatus which -detects or discovers the holes or defects in pipe coatings. When the coating consisted of a tar-like substance applied by hand, it was difficult to obtain a uniform surface, and any apparatus used to detect defects often became contaminated with the coating substance. Under such conditions detecting holidays was a very precarious and unsatisfactory procedure. Methods were constantly being sought by the industry to improve (1) the means by which pipe…