Engineering reminiscences contributed to "Power" and "American machinist" (1908)
Porter, Charles T. (Charles Talbot), 1826-1910 · New York, J. Wiley · leaf 129
the first one. The brass heads of thesprings were provided with three wings instead of two, which minehad. The spring, after being coaled and tempered, was brazedinto the grooves in the first two wings, and the third wing washammered firmly to it. This prevented the stress on the springfrom… … MANUFACTURE OF THE INDICATOR 87 spring was found. To insure freedom from friction, I determinedto adjust and test the springs in the open air, quite apart fromthe instrument. For this purpose I had a stout cast-iron platemade, with a bracket cast on it, in which the slides were held in avertical…
