. Bulletin - United States National Museum. Science. Figure i8.âTag Displaying Directions for Use of the Auburndale Timer. (In author's collection.) same dial was used on ni()\einenls indicatina; quarters and eighths of seconds, all being graduated in eighths. A dial without provision for indicating the fractions of a second on a separate small dial may be seen in figure 17. This last has been made into a stand for hair spring work and is shown with balance and spring just as it came from the .Xuburndale factory with balance spring and wheel for a timer still in place. The sweep second hand an
. Bulletin - United States National Museum. Science. Figure i8.âTag Displaying Directions for Use of the Auburndale Timer. (In author's collection.) same dial was used on ni()\einenls indicatina; quarters and eighths of seconds, all being graduated in eighths. A dial without provision for indicating the fractions of a second on a separate small dial may be seen in figure 17. This last has been made into a stand for hair spring work and is shown with balance and spring just as it came from the .Xuburndale factory with balance spring and wheel for a timer still in place. The sweep second hand and the minute register hand are attached to heart-shaped cams friction driven from their respective staffs. They are reset by a bar pivoted beneath the dial and actuated by the stem through pressure on the crown. An original instruction tag as sent from the factory with these timers is seen in figure 18. Figure 19 shows the mechanism of the split-second model as represented in U. S. patent 220195 of September 30, 1879, issued to William A. Wales and assigned to William B. Fowle.^° A split-second mech- anism is used to time the finish of two horses in the same race or any other similar event. In usual watches of this nature the watch will run along indefinitely with the extra or split second hand stopped although this hand will not record more than a difference of one minute from the main sweep hand. This was not true of the Auburndale, as pointed *" The mechanism was covered by British patent 3893, issued .September 27, 1879, to Philip .Syng Justice on behalf of William B. I'owle. out in the instructions. The reason for this is that motion is conveyed to this hand through a hair spring which would be damaged if allowed to overwind. To prevent this a stop is interposed which will the entire watch unless directions are followed. The serrated wheel /â¢â , of hardened steel, driving the second sweep hand, is cut on the edge with 120 serrations; stopping of thi
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Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
