r68 



NEW YORK STATE MUSEUM 



eters have been used, but one of very convenient and simple 

 form is somewhat as follows. It consists of a cylinder of sheet 

 iron which is jacketed with wooden staves. Inside of this there 

 is a spiral sheet copper tube which carries off the smoke from 

 the little fireplace, which is totally inclosed by double walls of 

 tin. The covering of the sheet iron cylinder already mentioned 

 has four openings, one for the smoke pipe leading from the 

 spiral tube, another one for the insertion of the thermometer, 

 a third for inserting a stirrer, and a fourth for filling the 

 cylinder. 



The fireplace has a grating with a small ash pit beneath it, 

 and these two have separate doors. The upper door, leading 

 into the fireplace, proper, has an opening for the admission of 

 air or draft, and a second for inserting a pipe leading from the 

 bellows. At one side of the cylinder is a stopcock for drawing 

 off the water. In using the apparatus the cylinder is filled to a 

 distance of 4 cm from the top with cold water, the exact volume 

 of which is known. The temperature of this water is deter- 

 mined before commencing the experiment. A weighed amount 

 of the peat is then placed on the hearth, set on fire, and the door 

 of the fireplace closed. Air is then pumped into the hearth by 

 means of the bellows. From time to time more fuel is added. 

 A.t the end of the experiment a note is made of the time which the 

 test has taken, the temperature of the water and the quantity of 

 the material burned. The percentage of ash is also determined. 

 Knowing then the amount which the temperature of the water 

 has been raised, the weight of the water used and the amount 

 of the fuel consumed, we can figure out the calorific power of 

 the peat. In order to obtain very exact results, a correction 

 should perhaps be made for the amount of heat absorbed by the 

 metal cylinder holding the water, though the loss of heat by 

 radiation through the walls of the cylinder is reduced to the 

 minimum by having it jacketed with wood, as before mentioned. 

 The amount of heat lost by absorption into the metal can be 

 determined by multiplying the weight of the metal cylinder by 



