FBOCKEDiyas of the Polytechxic AssocjATwy. Sill. 



The Cliairiuan remarked that this was a very important and 

 ingenious invention. We liave often heard of accidents to persons 

 from the hatches now in use. But in the hatch here presented it 

 seems these accidents cannot occur. Many of those present could 

 doul)tless remember M'hen there was no other device in use for hoist- 

 ing in warehouses but tlie ordinary tackle, and all the improvements 

 in tluit line have been made within the last fifteen years. The inven- 

 tion of Mr. Creamer is an important improvement on those now in 

 use, and should receive due consideration. A boy of ten years caii 

 work this hatch wdth ease, and it seems almost impossible for any 

 one to get it out of order. This inrention is a step in the proper 

 direction. It is to secure safety when we are more or less in danger. 

 All those operations which require heavy weights to be raised are 

 attended with danger. 



Dr. D. D. Parmelee said he thought this hatch one of those simple, 

 practical, common sense devices that should commend itself to theii- 

 earnest attention. It is a life-saving and a labor-saving machine. 

 This is an important consideration in a city like this, where there 

 are so many lives lost by the traps or hatches now in use. 



Mr. J. K. Fisher remarked that we often hear of firemen falling 

 through these traps, and he himself had often been in danger while 

 going through buildings down town. If a good strong fence was 

 placed around each hatch, it would save many accidents. 



Vapor Stove. 

 Mr. D. H, Lowe exhibited a vapor stove, which is announced on. 

 his circular as "" The greatest w^onder of the nineteenth century ! " 

 The stove was set in action at the close of the lecture, and seemed 

 to operate well, but elicited no discussion. To show that there was 

 no danger of explosion, the exhibitor ignited the vapor nt the top of 

 the cistern of liquid fuel, and allowed it to flame up vigorously, a 

 proceeding which, in this connection, indicated either great igno- 

 rance or consummate chicanery. It may be as well for the public, 

 who are frequently solicited to purchase inflammable fluid, to know 

 that vapor or gas will not explode until it is first mixed with a 

 proper proportion of atmospheric air. Ether, burning-fluid, hydro- 

 gen, coal gas, and all inflammable gas and vapors, will burn quietly 

 if they be not previously mixed with air, and the more vapor or gas 

 present in a given space the more quietly will they burn. It seemed 

 to be the opinion of tlie most exjierienced members of the Associa- 



