iQg ON THE HEAT DEVELOPED IK COMBUSTION. 



Fbtness of the The flat form of the worm is essential to the perfection 

 ■wormessen- f the apparatus; as is evident, wlien its purpose is con- 

 sidered. 



All the products of the combustion being elastic fluids, 

 end consequently substances incapable of communicating 

 their heat, but by proceeding particle after particle to 

 deposit it on the suface of the cold and fixed body intended 

 to receive it, it was indispensable so to construct the 

 apparatus, that the hot fluids should of necessity be spread 

 beneath and against a large flat surface, placed horizontally, 

 and always cold. 



Before I employed horizontal worms made of flat tubes, 



I had more than once tried those of the common form ; 



but they never answered my purpose otherwise than so 



imperfectly, that I could never make any account of the 



Tins *bape ad- experiments, in which they were employed. There is no. 



taniageotts for doubt b u t t} ie sna pe 1 have adopted for the worm of my 



ac&miBonstiH. , r . v 



calorimeter would be very advantageous for every kind qi 



apparatus for distillation. 

 Shape of the One thing very important in the construction of my 

 thermometer, apparatus is the shape of the thermometer, which I employ 

 to measure the temperature of the water in the receiver. 

 This thermometer, which I made myself; and which, after 

 having undergone every kind of trjal, has always appeared 

 good ; is a mercurial thermometer, divided according to 

 Fahrenheit's scale. It is one of four, all similar, that I 

 employed, at Munich, in the winter of 1802, in my ex- 

 experiments on the refrigeration of liquids enclosed ia 

 vessels. 



The reservoir of this thermometer is cylindrical^ about 



two lines in diameter only, and four inches high : and as 



the water in my calorimeter is four inches deep, this 



thermometer always indicates the mean temperature of 



the fluid, whatever may be the temperature of its different 



strata. 



fo measure In my various inquiries concerning heat, I have had 



irV- h fhe bulb ft" ec i uent opportunities of seeing the importance of this 



<f the iherrao- precaution ; and I cannot conceive how any one can 



meter should expect to avoid great mistakes in measuring the tempera- 



fcouonntotop. ture °^ liquids heated or cooled, if w,e do not attend to 



tins* 



