"
The materials to be drilled into medallions also required much
consideration. "I am much obliged to you," said Watt, "for the
balls, etc., which answer as well as can be expected. They make
great progress in cutting the crust (Ridgways) or alabaster, and
also cut marble, but the harder sorts soon blunt them. At any
rate, marble does not do for the medallions, as its grain
prevents its being cut smooth, and its semi-transparence hurts
the effect. I think Bristol lime, or shell lime, pressed in your
manner, would have a good effect. When you are at leisure, I
shall thank you for a few pieces, and if some of them are made
pink or flesh colour, they will look well. I used the ball quite
perpendicular, and it cut well, as most of the cutting is
sideways. I tried a fine whirling point, but it made little
progress; another with a chisel edge did almost as well as the
balls, but did not work so pleasantly. I find a triangular
scraping point the best, and I think from some trials it should
be quite a sharp point. The wheel runs easier than it did, but
has still too much friction. I wished to have had an hour's
consultation with you, but have been prevented by sundry matters
among others by that plaguey stove, which is now in your hands."
Watt was most grateful to Murdock for his unvarying assistance.
In January, 1813, when Watt was in his seventy-seventh year, he
wrote to Murdock, asking him to accept a present of a lathe "I
have not heard from you," he says, "in reply to my letter about
the lathe; and, presuming you are not otherwise provided, I have
bought it, and request your acceptance of it.
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