36 CALORIFIC POWER OF FUELS. 



in the sketch (Fig. 10), a certain quantity of sugar-charcoal, 

 the combustion of which was intended to accelerate and com- 

 plete that of the coal tested. 



In the figure (Fig. 10) ab represents the combustion-cham- 

 ber, c the calorimetric bath. Minor details of accessories, en- 

 velopes, regulators, etc., are omitted. The burner proper is of 

 platinum and of two pieces, a and b, superimposed, the coal 

 being placed in the lower portion, the sugar-charcoal in the 

 upper one. All pieces of the burner may be removed for the 

 introduction of the coal and for cleaning. The two combus- 

 tibles rest on perforated plates of platinum, in which the per- 

 forations, made by a special machine, are so small that light 

 can hardly pass through, and from which the cinders can be 

 completely removed ; the holes in the upper one are slightly 

 larger than those of the lower. The oxygen enters through 

 three tubes, e, f, g. Tubes g and m pass outside the bath, and 

 carry mirrors to allow inspection during the burning. The 

 waste gases pass off at the bottom through a coil n, and are 

 collected in H. This vessel is simply to detect smoking, he 

 having found that it happened only when the pressure was di- 

 minished at the burner, and that it could be stopped by a rein- 

 statement of the normal pressure. / represents an aspirator, in 

 which are collected the waste gases. Another one, not shown 

 in the sketch, serves to contain the gas analyzed. Both are 

 filled with water covered with a film of oil. The oxygen 

 passes through a jar s filled with soda-lime, a bottle o fur- 

 nished with a thermometer, a cock / as regulator of the flow, 

 and one or more wash-bottles q containing sulphuric acid. 



The calorimeter-chamber c contains 5200 cc. (4.6 qts.) of 

 water. 5 or 6 grams (77 to 92.5 grains) of coal were used, with 

 2 to 4 grams (3 1 to 62 grains) of sugar-carbon of a known 

 calorific value. The temperature of the bath rose about 10 

 C., and the experiment generally lasted an hour. 



The sugar-carbon was first kindled in the upper part of the 

 burner, the under portion burning first. From this sparks 



