KANSAS ACADEMY OF SCIENCE. ap 
II. CHEMISTRY AND PHYSICS. 
EXPERIMENTS ON THE RELATIVE HEATING POWER OF COAL 
AND ILLUMINATING GAS. 
BY E. H. S. BAILEY, UNIVERSITY OF KANSAS, LAWRENCE, 
Read before the Academy December 29, 1899. 
The problem that was brought to my notice some time ago was to find the 
relative fuel value of coal and natural gas, and, by this means, to determine how 
much per thousand should be paid for the latter so that the cost of fuel should 
be the same as if coal was used. Although we have the analysis of the natural 
gas as found in the Kansas gas fields,* and the composition of the coals of the 
state,t yet all attempts to arrive at the relative value of the two fuels froma 
theoretical standpoint were unsatisfactory, for the question was a practical one, 
and could be solved only by the use of a method that would imitate actual ex- 
perience. 
At first a crude apparatus was designed in which a weighed amount of water 
was boiled with a given quantity of fuel of each kind, but the loss of heat was so 
great that it was deemed advisable to construct an apparatus especially for the pur- 
pose. The furnace, as finally designed and used, is represented on next page. 
It consists of a cylinder of galvanized iron two feet high and fourteen inches in 
diameter. Inside of this is another cylinder ten inches in diameter and the an- 
nular space between the two is filled with charcoal, sawdust, or asbestos pack- 
ing. Both these cylinders are soldered onto the base and onto the connecting 
ring at the top. A bottom is soldered into the inner cylinder eleven and one-half 
inches from the base. Inside the vessel thus formed is a one-and-three-fourths- 
inch tin pipe coiled three times, the upper end opening above the top of the vessel 
and the lower end passing through the bottom. This is the flue to carry off the 
products of combustion. Below the bottom of the kettle is a small grate which 
may be removed and its place supplied by the burner of a gas stove. There isa 
door lined with asbestos on one side of the lower part of the furnace. Just below 
the grate are two one-fourth-inch iron pipes terminating on the inside, with el- 
bows turned upwards, and passing entirely through the apparatus to the outside. 
There is also a pipe leading from the bottom of the inside vessel closed by a spigot 
on the outside, so that the water may be quickly withdrawn from the inner vessel. 
A thermometer hangs in the water. 
The apparatus is used as follows: The inner vessel is filled with water, and is 
then heated to boiling by means of the gas-burner; this water is quickly drawn 
out by the spigot and weighed on a moderately accurate balance; with the vessel 
in which it is contained it weighs about twenty-four pounds. The water is im- 
mediately, while still hot, returned to the boiler, the gas is relighted and the 
amount of gas consumed is carefully measured by a meter that reads to hun- 
dredths of cubic feet. The gas is allowed to burn for an hour or more, and then 
the water is quickly drawn off and weighed. The difference gives the loss by 
evaporation, which is calculated per cubic foot of gas. 
In order to determine the heating power of the coal, the vessel is again filled 
*Kan, Univ. Quar,, vol. IV, pp. 1-14. }t Transactions Kans, Acad. of Sci., vol. XI, pp. 46-49. 
