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Watt's Famous Experiment of the Separate Condenser

This account is from the book by Thurston referenced below:

On Monday morning Watt proceeded to make an experimental test of his new invention, using for his steam-cylinder and piston a large brass surgeon's syringe, 14-inch diameter and 10 inches long. At each end was a pipe leading steam from the boiler, and fitted with a cock to act as a steam-valve. A pipe led also from the top of the cylinder to the condenser, the syringe being inverted and the piston-rod hanging downward for convenience. The condenser was made of two pipes of thin tin plate, 10 or 12 inches long, and about one-sixth of an inch in diameter, standing vertically, and having a connection at the top with a horizontal pipe of larger size, and fitted with a "snifting-valve." Another vertical pipe, about an inch in diameter, was connected to the condenser, and Watt fitted with a piston, with a view to using it as an "air-pump." The whole was set in a cistern of cold water. The piston rod of the little steam-cylinder was drilled from end to end to permit the water to be removed from the cylinder. This little model (Fig. 25) worked very satisfactorily, and the perfection of the vacuum was such that the machine lifted a weight of 18 pounds hung upon the piston-rod, as in the sketch. A larger model was immediately afterward constructed, and the result of its test confirmed fully the anticipations which had been awakened by the first experiment.

Fig.25.-Watt's Experiment.

From A History of the Growth of the Steam Engine, R. H. Thurston, see Bibliography.


Updated 11/22/12,Copyright 2001, Carl T. Lira, lira@egr.msu.edu. All rights reserved.
Prepared as a supplement to Introductory Chemical Engineering Thermodynamics.