The idea of having a neutral position built into the winding-setting stem of pocket watches was used by magicians during the time when such watches were in vogue (and sometime after). Other forcing approaches with watches were Robert Stull's multiple-setting pocket watch and Herbert Milton's double-faced hunter's case watch. Richard Himber updated the idea of the neutral stem-position in the 1960s with a specially altered wristwatch he sold as “Time Capsule”. At the same time, he released a wristwatch adaptation of the Stull watch, marketed as the “Ducatillon Mental Watch”. John Pomeroy found a diver's watch ready-made with a neutral stem position and explained that other wrist watches could be altered for the job by having a diver's crown installed. He published the idea in 1973, in Mentology (see “A Matter of Time”, p. 37). Bev Bergeron's contribution was discovering a cheap and popular brand of watches by Seiko with the required type of crown built in. Bergeron claimed to have run across this type of Seiko in 1969 (four years before Pomeroy's book was published, although probably not before he came up with the idea), but didn't publish the idea until 1989, in a manuscript, Predicting Time. Pomeroy's book is included in Bergeron's bibliography.