132 ANNUAL OF SCIENTIFIC DISCOVERT. 



original mechanical force remains as such, and that the remainder, converted 

 into heat, would be sufficient to raise a mass of water equal to the sun and 

 planets taken together, not less than twenty-eight millions of degrees of the 

 centigrade scale. For the sake of comparison, I will mention that the high- 

 est temperature which we can produce by the oxyhydrogen blowpipe, which 

 is sufficient to fuse and vaporize even platina, and which but few bodies can 

 endure, is estimated at about two thousand centigrade degrees. Of the 

 action of a temperature of twenty-eight millions of such degrees we can 

 form no notion. If the mass of our entire system were pure coal, by the 

 combustion of the whole of it only the 3500th part of the above quantity 

 would be generated. This is also clear, that such a development of heat 

 must have presented the greatest obstacle to the speedy union of the masses, 

 that the larger part of the heat must have been diffused by radiation into 

 space, before the masses could form bodies possessing the present density of 

 the sun and planets, and that these bodies must once have been in a state of 

 fiery fluidity. This notion is corroborated by the geological phenomena of 

 our planet ; and with regard to the other planetary bodies, the flattened form 

 of the sphere, which is the form of equilibrium of a fluid mass, is indicative 

 of a former state of fluidity. If I thus permit an immense quantity of heat 

 to disappear without compensation from our system, the principle of the 

 conservation of force is not thereby invaded. Certainly for our planet it is 

 lost, but not for the universe. It has proceeded outwards, and daily pro- 

 ceeds outwards into infinite space ; and we know not whether the medium 

 which transmits the undulations of light and heat possesses an end where 

 the rays must return, or whether they eternally pursue their way through in- 

 finitude. 



The store of force at present possessed by our system, is also equivalent 

 to immense quantities of heat. If our earth were by a sudden shock 

 brought to rest on her orbit which is not to be feared in the existing ar- 



o O 



rangements of our system by such a shock a quantity of heat would be 

 generated equal to that produced by the combustion of fourteen such earths 

 of solid coal. Making the most unfavorable assumption as to its capacity 

 for heat, that is, placing it equal to that of water, the mass of the earth 

 would thereby be heated 11,200 degrees; it would therefore be quite fused 

 and for the most part reduced to vapor. If, then, the earth, after having 

 been thus brought to rest, should fall into the sun, which of course would be 

 the case, the quantity of heat developed by the shock Avould be four hundred 

 times greater. 



Even now, from time to time, such a process is repeated on a small scale. 

 There can hardly be a doubt that meteors, fire-balls, and meteoric stones, are 

 masses which belong to the universe, and before coming into the domain of 

 our earth, moved like the planets round the sun. Only when they enter our 

 atmosphere do they become visible- and fall sometimes to the earth. In 

 order to explain the emission of light by these bodies, and the fact that for 

 some time after their descent they arc very hot, the friction was long ago 

 thought of which they experience in passing through the air. We can now 

 calculate that a velocity of 3,000 feet a second, supposing the whole of the 



