The melamine resin dials do usually have cracks and hairlines after a few decades. It does not easily burn and is very resistant to chemicals. On old light switches or old electrical sockets. Melamine resin (melamine formaldehyde) was one of the first widely used plastics. Hamilton had in the 1920's a sales and marketing brochure called the Timekeeper and it had a chapter explaining those adjustments: hamilton_adjustments.pdf, 238794 bytesĭial material: a few models had porcelain enamel (aka vitreous enamel) on brass but most are made of a melamine resin (plastic) coated brass plate. It's the positional adjustment and the temperature adjustment that sets this watch apart from many others made in the 1940's.Īdjustment for isochronism means that the watch runs with the same rate independent of whether the watch if fully wound or almost unwound. The 6 positions are: (1) dial up, (2) dial down, (3) stem up, (4) stem at 9 o'clock and (5) stem at 3 o'clock, (6) stem down at the 6 o'clock. It is done to maintain approximately the same rate of balance wheel oscillation, regardless of which of the specified positions the watch is in. The little weights on the balance wheel are an important part of that adjustment. Position adjustment refers to the mechanical design of the balance wheel and the hairspring. The watch runs about 52 hours when fully woundīalance wheel: Aurium, a monometallic beryllium-silver-nickel alloy, Aurium is a Hamilton marketing term (trademarked in April 1940 by Hamilton), the exact composition of the alloy was kept secret.Īdjustement: temperature, isochronism and 6 positions Rate: 2.5Hz, 5 beats per second, 18000 bph (beats per hour) Jewels (gemstone bearings): 21, friction set, all upper jewel settings are gold
Movement size: 16, 1.700 inches, 43.18 mm diameterĪpproximate watch size (depends on case): 2 inch (5cm) diameter, weight 90g It has a beautifully decorated movement.Ī 1948 Hamilton Railway Special, grade 992B, 21J The Hamilton 992B pocket watch is a beautiful watch not only on the outside. In this article we focus however on watches and it is this focus on timing only that lead to those beautiful and precise American railroad watches. Ball January 16, 1910).Īn interesting question from a historic point of view is of course: why did nobody in North America come up with any solution other than time keeping? Many other countries solved the root cause of the problem with station to station communication, signaling, tokens or dual track. He gave a very interessting interview in the New-York Tribune Janu( Many lives sacrificed because of faulty watches, interview with Webb C. Ball's career eventually led to him being the time inspector on more than half the United States' railways, leading to a far more uniform set of standards across the US. His first job as a time inspector was when he was brought in by the Lake Shore and Michigan Southern Railways in 1891 after a crash and was tasked with bringing their time inspection system up to industry standards. These railways had a single track for both directions and two trains running in opposite direction could pass each other at railway stations and other places which had two tracks, one for each direction, for a short distance only.Ī notable watch inspector was Webb C. Regular watch inspection and consistent time keeping was the only thing that kept trains from running into each other on Americas single track railways. The need for Railroad Watches to be "railroad approved" stemmed from a number of train accidents in the late 1800's where two trains collided head on due to poor time keeping. A lot of other mechanical watches are off that much in just one day. Then you will achieve about +/- 15sec accuracy Is exposed to different temperatures and shaken or turned A well maintained and adjusted watch kept inĪ fixed location at room temperature can reach accuracies The Hamilton grade 992B is a high quality antique mechanical pocket watch. The Hamilton 992B Railroad Pocket Watch, Hamilton Railway Special Hamilton 992B Railroad Pocket Watch, Hamilton Railway Special
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