FROM UlPPERENT AIM' V If LTU8 



•;ory inspection of the numbers in the first column of the table, 

 the second column of numbers lias been inserted to facilitate 

 these comparisons, and the great disparity in the quantity ol 

 fuel required to produce the same effect in No. 1 and No. 2, may, 

 at first view, appear paradoxical, if compared with the quantity 

 of heat saved by each, from 100 parts generated, as onlj 8 parts 

 more heat are saved by No. 2, than is saved bj No. I, and 

 yet the positive saving in fuel by using No. 2. is nearly I pi I 

 cent. 



To find the numbers in the second column, we assume th< 

 fuel used in all the experiments as 100; and tor the facility ol 

 comparison, we will say this quantity of fuel maintained tin 

 temperature of the room 100 minutes when consumed in ap 

 paratus No. 9. In experiment No. l,we find this quantity 

 of fuel maintained the temperature of the room only 10 

 minutes, and, consequently, it would have required 10 times 

 as much fuel as apparatus No. 9, (or 1000,) to maintain tin 

 room at the same temperature for 100 minutes. In the sunn 

 manner the other numbers arc found. 



The proportion for the experiments will be clearly explained 

 in the following manner: As the time of the experiment is to 

 the quantity of fuel consumed, so is the assumed time of com- 

 parison, to the fuel that would be required for (hat time. Thus 

 for experiment No. 2: A- 18 : 100 : : 100 : 556. 



By an examination of the numbers in the second column oi 

 the table, it will he seen that one dollar expended in fuel con 

 sumed in apparatus No. !>, is as effective as ten dollars expended 

 in the same kind of fuel consumed in No. I, the same quantity 

 of heat being imparted to the room in both casi a. Th< com 

 parison may be extended in the Bame manner between anj 

 two experiments inserted in the table, and the figures in th< 

 second column will be found to express the n lative vslvu of fuel 

 for each apparatus, in dollars and cents. |,\ adding a decimal 

 point at the left hand of the two last figures. 



Experiments No. 6, ?. and 8, were made with the same 

 stove tor the purpose of determining the diffi rence in the I 

 of heat by different constructions and posHiene ol pip< ol th< 



