ON THE HEAT DEVELOPED IN COMBUSTION. 107 



Combustion of the inflamable substances burned in the ex- 

 periments; and transmitting the heat manifested in this 

 combustion to a considerable body of water, which is in the 

 receiver. 



This worm, which is made of thin copper, occupies and 

 covers the whole bottom of the receiver, yet without touching 

 either its bottom or its sides. It is a flat tube, an inch and 

 half broad at one end, and an inch at the other ; and half an 

 inch thick throughout. It is bent horizontally, so as to pass 

 three times from one end of the receiver to the other ; and is 

 supported in its place, two lines above the bottom of the re- 

 ceiver, by several little feet. 



The aperture, that forms the mouth of the worm, is a cir- 

 cular hole in its bottom, near its broadest end. Into this 

 hole is soldered a perpendicular tube, an inch in length and 

 an inch in diameter, reaching within the worm to the height 

 of a quarter of an inch above its bottom. 



This tube passes through a circular hale in. the bottom of 

 the receiver, to which also it is soldered. Its lower aperture 

 is seven lines below the bottom of the receiver; and through 

 this the products of the combustion enter into the worm. 



The other extremity of the worm passes horizontally through 

 the perpendicular end of the receiver, opposite to that near 

 which the products of the combustion enter the worm. 



The worm, before it passes through the end of the receiver, 

 is fashioned into the shape of a round pipe, half an inch in 

 diameter; and an inch in length of this pipe is seen without 

 the receiver. This piece is made to fit tight into another 

 similar tube, belonging to the worm of another receiver, 

 which 1 call the secondary receiver ; the purpose of which Secondary re. 

 is to receive the heat, that might still be found in the ceiver - 

 products of combustion, after they have passed through the 

 worm of the principal receiver. 



To support these two receivers in the air, so as not to touch Mode of sup- 

 the table that supports them, each of them is fixed in a frame portlng them ' 

 of dry linden wood, made of rods an inch square. Round 

 the bottom of each receiver is a copper rim, three lines deep, 

 which is fastened by a row of very small nails to the wooden 

 frame. The body of the receiver it* elf enters about a line 

 into the frame, to which it is very accurately fitted. 



The 



