Workshop notes for jewelers and watchmakers : being a collection of the latest practical receipts on the manufacture and repairing of watches and clocks, and on the various processes entering into the manufacture and repairing of jewelry, as coloring, polishing, enameling, annealing, oxydizing, etc. ... (1899)
Brassler, Charles · New York : Jewelers' Circular Pub. Co. · leaf 308
pinion . stone and shorten. If the long escape To Adjust the Drop or Impulse: teeth are found to be either shallow or See that the upright teeth have from four to ten degrees of locking. If more or less deep (short or long), do not attempt to shorten or lengthen. This is a rare occur¬ drop then… … finger and turn same either direction to give more or less drop, as desired. IMPULSE MOVER.
Clock and watch making · Goldwork · Silverwork · Jewelry
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.