Lot Essay
The frame is incised with the frame makers' punch-mark "J P" and numbered 2812. The mark is of Joseph Preston of Prescot. He made chronometer frames for Bliss, Kullberg and a great many chronometer makers.
The balance appears to be of unrecorded format. However John Bliss is recognized as being one of the few American chronometer makers who in the late 19th Century was experimenting in the design and construction of compensation balances. In 1892 he submitted the specifications of one of these to the United States Patent Office (Letters Patent No. 492184 dated February 21 1893); the drawings of this patent do not in any way resemble the balance fitted to No. 2812. There is, however, a resemblance to Kullberg's flat rim balance but Kullberg's lacks the form of vertical heat compensation weights described above (see Gould The Marine Chronometer, 1923, fig. 74, see also lot 86) . The shape of the vertical weights are not dissimilar in appearance to those in Charles Frodsham's compound micrometric balance (vide Vaudrey Mercer The Frodshams, AHS, 1981, plate 62, pp. 405); the Frodsham vertical weights are of one piece turned from one piece of rod, whereas those fitted in No. 2812 are two distinctly separate weights, the upper of white metal the lower of brass.
Imperial College of Science, Technology and Medicine Analysis
It is the vertically mounted white metal discs that evoke horological interest. These discs are an almost immovable fit on the threaded brass rod above the lower smaller brass heat compensation weights and it was considered imprudent to attempt to unsrew them prior to analysis. One complete assembly was removed from balance and submitted to the Department of Materials, Imperial College of Science, Technology and Medicine, London (1 April 1998) for analysis under their GEAL T-200 Scanning Electron Microscope, to a magnification of X20,000.
The result of the qualitative analysis showed the outer surface of the upper white metal disc is platinum; the quantitative analysis by weight and volume came to a viable conclusion that it was made of platinum throughout. It is of particular historical horological interest that over 100 years ago an American chronometer maker should have been experimenting using solid platinum - a highly costly material in those times - in such a quantity in the construction of what must have been an experimental chronometer balance.
The probability must considered that this particular balance may well have been constructed by Arthur C. Fox who was an outstanding American chronometer maker working for Bliss. He is recorded as owning a collection of balance affixes designed to overcome middle temperature error (vide Marvin Whitney The Ship's Chonometer, American Watchmaker's Institute Press, Cincinnati, 1985, pp. 341, and Paul M Chamberlain, It's About Time, The Holland Press, 1978, pp. 438 and 439); our thanks to the Imperial College of Science, Technology and Medicine for their help
The balance appears to be of unrecorded format. However John Bliss is recognized as being one of the few American chronometer makers who in the late 19th Century was experimenting in the design and construction of compensation balances. In 1892 he submitted the specifications of one of these to the United States Patent Office (Letters Patent No. 492184 dated February 21 1893); the drawings of this patent do not in any way resemble the balance fitted to No. 2812. There is, however, a resemblance to Kullberg's flat rim balance but Kullberg's lacks the form of vertical heat compensation weights described above (see Gould The Marine Chronometer, 1923, fig. 74, see also lot 86) . The shape of the vertical weights are not dissimilar in appearance to those in Charles Frodsham's compound micrometric balance (vide Vaudrey Mercer The Frodshams, AHS, 1981, plate 62, pp. 405); the Frodsham vertical weights are of one piece turned from one piece of rod, whereas those fitted in No. 2812 are two distinctly separate weights, the upper of white metal the lower of brass.
Imperial College of Science, Technology and Medicine Analysis
It is the vertically mounted white metal discs that evoke horological interest. These discs are an almost immovable fit on the threaded brass rod above the lower smaller brass heat compensation weights and it was considered imprudent to attempt to unsrew them prior to analysis. One complete assembly was removed from balance and submitted to the Department of Materials, Imperial College of Science, Technology and Medicine, London (1 April 1998) for analysis under their GEAL T-200 Scanning Electron Microscope, to a magnification of X20,000.
The result of the qualitative analysis showed the outer surface of the upper white metal disc is platinum; the quantitative analysis by weight and volume came to a viable conclusion that it was made of platinum throughout. It is of particular historical horological interest that over 100 years ago an American chronometer maker should have been experimenting using solid platinum - a highly costly material in those times - in such a quantity in the construction of what must have been an experimental chronometer balance.
The probability must considered that this particular balance may well have been constructed by Arthur C. Fox who was an outstanding American chronometer maker working for Bliss. He is recorded as owning a collection of balance affixes designed to overcome middle temperature error (vide Marvin Whitney The Ship's Chonometer, American Watchmaker's Institute Press, Cincinnati, 1985, pp. 341, and Paul M Chamberlain, It's About Time, The Holland Press, 1978, pp. 438 and 439); our thanks to the Imperial College of Science, Technology and Medicine for their help