' 70 On the Origin of Stones 



plosion and report. 6. That they fall on the earth with 

 great force in a sloping direction. 7- That they are very 

 hot at first, remain hot a considerable time, and exhibit 

 visible tokens of fusion on their surface. 8. That the fallen 

 stonv masses have all the same external appearance and 

 contexture, as well as internallv the same nature and com- 

 position. 9- That they are totally different from all our 

 terrestrial bodies, both natural and artificial. 



" Now tliese phceuomena will naturally compare with 

 the circumstances of a substance projected by a lunar vol- 

 cano, and in the order in which they are here enumerated. 

 And first with respect to the leading circumstance, that of 

 a ?adden blazing meteoric appearance, which is not that of a 

 sn)all bright spark, first seen at immense distance, and then 

 gradually'increasing with the diminution of its distance. 

 And this circumstance appears very naturally to result from 

 the assumed cause. For the body being projected from a 

 lunar volcano, may well be supposed in an ignited slate, 

 like inflamed matter thrown up by our terrestrial volcanoes, 

 which passing through the comparatively vacuum, in the 

 space between the moon and the earth's sensible atmo- 

 sphere, it will probably enter the superior parts of this 

 atmosphere with but little diminution of its original heat; 

 from which circumstance, united with that of its violent 

 motion, this being 10 or 12 times that of a cannon ball, 

 and through a part of the atmosphere probably consisting 

 chiefly of "the inflammable gas, rising from the earth to the 

 top of the atmosphere, the body may well be supposed to 

 become suddenly inflamed, as the natural effect of these 

 circumstances ; indeed it v/ould be surprising if it did not. 

 From whence it appears that the sudden inflammation of 

 the body, on entering the earth's atmosphere, is exactly 

 what might be expected to happen. 



'^ 2. Secondlv, to trace the body through the earth's 

 .itmosphere, we are to observe that it enters the top of it, 

 with the creat velocity acquired by descending from the 

 point of equal attraction, which is such as would carry the 

 body to the earth's surface in a very few additional seconds 

 of time, if it met with no obstruction. But as it enters 

 deeper in the atmosphere, it meets with still more and 

 ^ more resistance from the increasing density of the air ; by 

 which the great velocitv of 6 miles per second must soon be 

 greatlv reduced to one that will be uniform, and only a 

 small part of its former great veloci*y. This remaining 

 part of its motion will be various in difl'erenl bodies, being 

 morj or less as the body is larger or smaller, and as it is 



more 



