Check out this URL for "PV Scientific" that I found while doing a web search for "tesla coil". "Working Models of Scientific Instruments that Produced Great Discoveries in Electricity, Magnetism and Atomic Physics" http://www.clarityconnect-dot-com/webpages/justjillw/pvsci/default.html >From there follow the link to their reprint page (if you can get past the pictures of turn-of-the-century electrical apparatus;) jim