National Geographic : 1920 May
00F 0 WATCH WOL IN The Waltham Scientifically Shaped Guard Pin that Means So Much to You in Time-keeping Accuracy JUST as the flange on the wheels of the railroad train keeps it from running off the track, so the Waltham scientifi cally shaped guard pin keeps the escapement from going out of action. It is these little things of scientific con struction which insure dependable per formance. And this is particularly true of a watch. This Waltham guard pin is a Waltham 71/2 Ligne The movement is actually smaller than a dime in diameter $250 to $1,500 or more depending upon the case scientifically shaped development of Wal tham genius- curved in shape for a reason, which overcomes the errors of time-keep ing found in watches with a straight guard pin. The position of any guard pin is deter mined by the diam eter of the roller (il lustrated above), and after the escapement has been adjusted, the guard pin is bent for- ward to within a third of the thickness of a human hair, to allow the roller to revolve freely, excepting when the watch receives an unusual jolt, and that is the time the guard pin functions. In other words, the guard pin is a safety device to assure the perfect functioning of your watch. You will notice in the illustration that the Waltham scientifically curved guard pin presents a single and infinitesimal point of contact with the roller, thereby reducing the possibility of friction which is the greatest enemy of good time-keep ing. The straight guard pin presents, if prop erly made, a plane of contact. If there should be any imperfection, the guard pin would have to be set at an angle. (See illustration above.) And this would make it impossible to properly adjust the guard pin. Whereas the curved guard pin can be bent in any direction and it will still present its small area of contact, reducing friction to a minimum. It is these tiny, exclusive units hidden in the works of the watch, involving years of study and invention, that assure you of precision time keeping and durability when your watch selec tion is a Waltham. This story is continued in a beautiful booklet in which you will find a liberalwatch education. Sent free upon request. Waltham Watch Company, Waltham, Mass. WALTHAM THE WORLD'S WATCH OVER TIME "Mention The Geographic-It identifies you"