292 P. E. Chase—Method of Estimating the Sun’s Mass. 
so far as observed, resemble those of Zzodon. In Clidastes, the 
only scutes detected were some fragments adhering to the 
caudal vertebree of C. Wymani Marsh. They are very thin, 
and quite smooth. 
he various specimens examined in this investigation render 
it probable that the cranium of these reptiles was not cove 
with plates, but the body only, as in some of the Crocodilia 
The scutes are apparently different in each species, and hence 
are important as a means of identification. 
Yale College, New Haven, March 5th, 1872. 
Art. XL.—A New Method of Estimating the Sun’s Mass and 
Distance, by means of the Heating Energy of Flames ; by Pt 
EARLE CHAsk, Professor of Physics in Haverford College. 
In a recent paper* I endeavored to demonstrate, from f- 
miliar postulates, the following proposition : ae 
The kinetic energy of dissociated water should be to the kinehe 
energy of terrestrial revolution, as the mass of the earth is to the mass 
of the sun ; ce 
And the energy of hydrocarbons should be to the energy 2 dis- 
sociated water, as elastic energy, under constant volume, 1s to elastic 
energy under constant pressure. ¢ 
As the proposition has obvious important bearings, I submit 
to the readers of this Journal the following illustrations of my 
method. 4 
arious experimenters have estimated the heating equiv® 
lents of chemical combination, for hydrogen and other elemen 
tary and compound substances. The earlier estimates are Very 
discordant, but successive improvements in apparatus led to a 
satisfactory approximation of results. 
olecular, as well as cosmical forces, being presumably cet 
ure- 
ments of those energies, but I am not aware that any on¢; ga 
* Read before the American Philosophical Society, Feb. 16, 1872. 
+ Proceedings and Trans. Amer. Phil. Soc.; this Journal, 1863-4, et sv». 
