PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 483 



device, however, is the enormous friction, and there is considerable loss 

 from the facility with which the water runs back. Tiie velocity with which 

 some valves work is very great, and they wear out very fast. There is a 

 pump made in Portland that is used on steam fire engines, which has no 

 valves, but has a hollow plunger connected to one end of the rod of the 

 engine, and it is said to work well. (Mr. Watson illustrated his remarks 

 by diagrams on the blackboard of the various pumps spoken of.) 



Mr. T. D. Stetson remarked that many improvements had recently been 

 made in pumps, owing to the demand for them at the oil regions, where the 

 value of a good article is appreciated, and hence inventors sire now devot- 

 ing much attention to this matter; and which would, no doubt, result in 

 some important advantages. 



The Chairman remarked that great improvements in the pump have been 

 made in this country. The first object was to obtain a cheap pump for 

 household uses. This was accomplished, some thirty years ago by Mr. 

 Minor, a very ingenious mechanic of Western New York, who made the 

 first cheap wooden pump. By means of machinery, he was enabled to 

 bore the inside, turn the outside of a piece of scantling, and cut a screw 

 on each end at one operation. The whole time occupied being but little 

 more than one minute. The stock was also turned from wood. The only 

 iron parts of the pump, were the cylinder, the valves, and the pump- 

 liandle. This very cheap pump had an extensive sale. Several persons 

 retired with fortunes made in its manufacture. It was soon found that the 

 stock could also be made of iron, with less trouble than of wood, and that by 

 placing the piston in this stock, which formed the cylinder, there was in 

 fact a great saving. This kind of pump in various forms has long been 

 made in large numbers at Seneca Falls in this State. Probably there is 

 no place in the woi'ld where more pumps are turned out as rapidly as at 

 this place. Pumps for nearly all uses are made there, and one of the few 

 good rotary pumps was invented and first made there by Birdsall Holley. 

 It is a modification of the pump formed by two wheels gearing into each 

 other, by means of which a continuous stream is furnished. After further re- 

 marks, "Telegraphs" was selected as the next subject for discussion. 



Adjourned to February 9th. 



American Institute Polytechnic Association, ) 

 February 9lh, 1865. ) 



Prof. S. D. Tillman in the Chair. 



Sheaves or Rollers for Sliding Doors. 



A model of Hatfield's sheaves for sliding doors was exhibited, and 

 explained by Mr. Capron. By this arrangement the superior advantages 

 of a roller over those of a wheel are secured in moving a door, or any 

 other burthen having a reciprocating motion. In the ordinary form the 

 roller is inapplicable to a sliding door; but, by a modification, as shown 

 in this sheave where the burthen presses on an axle, instead of the peri- 

 phery of the roller, the distance traveled by the roller is so much lessened 

 that its application to the sheave is quite practicable. In common sliding 



