Account of a new Pummice Press* 117 



not more than two days work , for a carpenter, to compleat 

 the press ; and this estimation of time is not guess work, 

 but the result of experiment. A carpenter's apprentice 

 assisted me in the sawing of the plank for one day, and 



1 completed it on the second day. The plank which is 



2 1-2 inches thick, delivered at my door, cost me two 

 dollars and one half, and the chain, pin, and a hundred 

 of 4d cut nails for the cribb, is the whole expence of 

 iron work. So that this may be considered as much 

 the cheapest, as well as the most powerful press yet 

 known, and any farmer who can handle a saw, an axe, 

 and an augur, can readily make the whole ; especially 

 considering, that a strong withe may supply the place 

 of the chain, and a tough piece of hickory the place of 

 an iron pin. 



The pressure of the weight ( 100 pounds) on the pum- 

 mice, is as 5 times 5 is to 1. That is, its pressure down- 

 wards is equal to 2500 pounds. But, the uprights being 

 fastened to the side planks, the toe of each lever bears 

 the cribb upwards with the same power as the heel (or 

 fulcrum) presses do^vn wards ; so that the actual pressure 

 on the pummice is equal to 5,000 pounds. 



The press from which this is sketched, is provided 

 with two of these compound levers acting side by side, 

 and consequently press equal to 10,000 weight; al- 

 though the uprights are only five inches apart, and by 

 lengthening the pin, which supports the levers only five 

 inches, two more of those levers may be added, on the 

 outsides of the uprights, which will press equal to ano- 

 ther 10,000 pounds, and so infinitely. 



The floor of the press is perforated with two augur 

 holes, of an inch and quarter diameter; and on the floor 



