482 TRANSACTIONS OF THE 



gave an interesting account of the origin and history of his improvements. 



Mr. Shultz exhibited a model of his new cut-off for steam engines, which 

 has been in operation at the Palace Garden. Its novelties are, the use of 

 only one sliding valve, which is balanced. It is moved by the action of 

 the governor, through the medium of revolving cams, so as to cut off the 

 Bteam at any point, during the whole stroke. The point of cutting off is 

 constantly shown by a pointer, moving in a right line over a graduated 

 scale. It has, also, a lever, by which the engineer can reverse the motion 

 with great facility. This invention seemed to meet with very general 

 approval. 



Mr. Westbrook then explained the construction of his churn, to which he 

 has given the name of "Butter Mill," It is intended to separate the but- 

 ter particles from new, sweet milk, and is claimed to be an improvement on 

 Johnson's churn, which was exhibited before the Polytechnic lasf- year. 



Mr. Hoao'land exhibited some of the material from which he makes his 

 earth paint, having impressions of the vegetable remains supposed to have 

 modified the action of the iron, and produced a peculiar mixture with clay 

 which has no perceptible grit. 



Mr. Seeley having been down to the bottom of the East Ptiver, on 

 Wednesday, in "Ryerson's diving bell," was called \ipon and gave a very 

 interesting account of his descent, and of the peculiarities of the apparatus. 

 The main feature of difference between it and the famous "Nautilus" 

 diving bell, also of American origin, is in the manner of providing fresh 

 air for breathing purposes. Mr. Eyerson does not take air from the atmos- 

 phere, but by means of a spray pump, throws into the bell water which 

 always contains a small quantity of air, having more oxygen in it than 

 is found in common air. The main effect of the pump is evidently to 

 absorb the carbonic acid thrown off from the lungs. The machine is said 

 to have been in successful operation during the past summer. 



.After further discussion on diving bells, the Association decided to con- 

 tinue the subject of " Novelties at the Fair," and adjourned to Thursday 

 evening, Nov. 3d. 



Polytechnic Association of the American Institute, > 



Nommher Zd, 1859. S 



S. D. Tillman, Esq., in the chair. Mr. Haskell, Secretary, pro tern. 



After reading the minutes of the last meeting, Mr. Arnold's Lamp Stove 

 was exhibited, and its uses were explained by Mr. Stewart. It can be em- 

 ployed as a feet warmer and general heater in a small way, and is compara- 

 tively inexpensive. 



Mr. Garbanati introduced the subject of the employment of steam, or 

 rather its economizing, by the use of condensers, and wished to know if any 

 of the judges who examined Prosser's Steam Condenser were present, aind 

 would explain its construction and probable efficiency. 



Mr. Garvey, one of the judges, objected to the introduction of any man's 



