Footnotes

• James Watt (1736-1819) is certainly more famous for devising and improving the cylinder piston steam engine, however smaller projects such as the copying machine, measuring distances accurately using telescopes and the statue copier, took up his time towards the end of the 18th Century.
  
  This copying machine design was the result of Watt, tirelessly copying by hand, key correspondence between himself and that of his business partner, Matthew Boulton. Boulton & Watt being the business name, were historically responsible for the design and installation of the larger fixed steam engines in mills, mines and factories.
  
  After many attempts in the early 1780s, Watt worked with a damp tissue idea for ink-bleed to run from the original surface to another.
  In W. B. Proudfoot's book The Origin of Stencil Duplicating(p. 21), the full descriptive operation process is:
  ...in the process used on James Watt's copying machine the letter-to-be-copied was written with a special copying ink on a sheet of good quality paper and placed, when dry, in contact with a water-dampened tissue-paper. The two were held together for a few minutes in some form of mangle or screw press. The writing which offset on to the tissue gave an impression in reverse, but as the tissue was very thin it was simple to read the writing from the other side where it appeared the correct way round... The writing was dried without blotting or application of heat, and contact with the dampened tissue was best made within twenty-four hours of writing the original. A full prescription or recipe for the ink is described in the patent. The process depended on the nature, quality and freshness of the ink, on the essential thinness of the paper tissue, and on the papermaker's ability to make it tough and durable when wet...
  
  

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Category: Collectibles / Scientific Instruments

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