Heat engendered by the possibie Fall of a Meteor into the Sun. 889 
per second, the corresponding rise of temperature is 564°, in- 
creasing as the square of the velocity ; and 419 miles per second 
corresponds to 419 x 419 x 564=99,016,404°. 
A pound of iron under the same circumstances would acquire 
the same force ; but that force converted would raise its tempe- 
rature nine times the above amount, because the same quantity 
of heat has nine times greater effect in raising the temperature 
of iron than it has on the same weight of water. 
A pound of mercury would have its temperature affected about 
thirty times the above amount, and so on according to the specific 
heat of the substance. 
Assuming that the specific heat of the body that impinges on 
the sun is the same as glass, the rise of temperature correspond- 
ing to the velocity 419 miles per second is 565 million degrees 
Fahrenheit. 
Thus the intensity of the temperature engendered depends on 
the molecular constitution of the body : the quantity of the heat, 
however, is independent of everything but the velocity and the 
mass; and each pound of any body whatever that strikes the sun 
with the velocity 419 miles per second is endowed with force 
sufficient to raise a pound of water 100,000,000 degrees of Fahr- 
enheit’s scale. 
Has the mass of the sun been gradually collocated by matter 
thus descending? To estimate exactly the probability of this, 
two other data are required, viz. the temperature of the sun’s 
surface, and the quantity of heat radiating from it in a given 
time. The first is unknown, but the second we know approxi- 
mately from the observations of M. Pouillet, also from those of 
Herschel and Forbes. It is estimated that it suffices to melt 
a stratum of about 2 feet thickness of ice at the earth’s mean 
distance in twenty-four hours. This is equivalent to 1:04 foot 
of ice per second at the sun’s surface. Now it is known that 
ice requires 142° F. to melt it, and each of those degrees is 
equivalent to the work expended in raising the weight of the ice 
772 feet against the force of gravity at the earth’s surface. We 
thus deduce that a weight equal to that of the ice arriving at the 
sun with a velocity of 2649 feet, or half a mile per second (viz, 
the velocity acquired in falling through 142 x 772 feet), is equi- 
valent to the force emanating from the sun in one second. If 
the same amount of force is brought to the sun by matter moving 
at the minimum velocity of 419 miles per second, the mass of 
this matter must be less than the mass of the ice, in the ratio of 
1 to the square of twice 419. Such a mass is represented by a 
sphere of 11-068 miles in diameter, of the density of water. 
Supposing the sun to have the same density and specific heat 
as water, and comparing its volume with that of the sphere of 
