Classically Trained Slide Rule (Slipstick) Mechanical Analog Calculator. Graphic of a Slide Rule with the phrase Classically Trained. Great nostalgic gift for retired engineer, math teacher, scientist, college professor from the boomer & silent generations Old Fashioned Slide Rule. Vintage Analog Calculator Design. Reminder of the time when physicists, engineers, scientists, and professors used slipsticks to calculate logarithms. This throwback is sure to bring back memories at your next college reunion! Lightweight, Classic fit, Double-needle sleeve and bottom hem