CATALOG OF THE MECHANICAL COLLECTIONS 99 



The separator is a cast-iron cylinder, 2 feet in diameter, with a 

 depth at the circumference of 14 inches. The top of the cylinder 

 is double walled and slightly domed, with an opening at the center 

 121^ inches in diameter. It is mounted upon a short vertical shaft 

 that carries a horizontal belt pulley. A heavy cast-iron bedplate 

 supports the bearing of the shaft and carries two stub shafts for 

 idler pulleys to guide the driving belt to the shaft pulley. The scoop 

 pipe and filling faucet are missing. 



In use mill?: was run into the cylinder from a faucet through the 

 opening of the top, and the cylinder was spun at a rate of 1,600 

 revolutions per minute. In about 20 minutes centrifugal force would 

 have thrown the heavier milk to the wall of the cylinder and the 

 cream would have formed an inner layer inside of the milk. A scoop 

 pipe was inserted through the opening into the revolving layer of 

 cream, which ran out through the pipe to cans. Fresh milk was 

 added to bring the level of cream and then the skim milk up to the 

 scoop pipe. The separator had a capacity of about 516 pounds of 

 milk an hour. It was driven by belting from the line shaft of the 

 dairy, which was powered by a l-horsepower steam engine. 



A discussion of the equipment at the Deerfoot Farm dairy and a 

 brief history of centrifugal milk separators are contained in the arti- 

 cle "Deerfoot Farm Centrifugal Dairy", by E. Lewis Sturtevant, in 

 the Annual Re-port of the Commissioner of Agriculture for the Year 

 1880, Washington, 1881. 



THOMSON AND HOUSTON CENTRIFUGAL CREAMER, 1881 



U.S.N.M. no. 309134 ; original patent model ; transferred from the United States 

 Patent OflSce ; not illustrated. 



This model, which is roughly diagrammatic, was submitted with 

 the application (1877) for the patent issued to Elihu Thomson and 

 E. J. Houston, of Philadelphia, April 5, 1881, no. 239659. 



The creamer represented by the model is a centrifugal separator 

 with a single source of supply and two distinct discharges designed 

 to give continuous operation without interference of the supplied 

 liquid with the separated products. Stopping the apparatus for the 

 insertion and removal of material, "as in ordinary centrifugal ma- 

 chines", is unnecessary. 



The separator has a conical-shaped rotating case on a hollow ver- 

 tical shaft, which opens into the bottom of it, and a horizontal de- 

 flector plate a few inches above the bottom. The liquid is supplied 

 from a pipe above the center of the central top opening of the case. 

 The deflector plate prevents the passage of the supplied liquid di- 

 rectly to the hollow shaft. Under the influence of the rapid rotation 

 of the case the denser ingredients of the liquid accumulate toward the 



