12 
‘Tf, then, these observations may be accepted to be good for any 
part of space, we may, and indeed must, expect celestial pheno- 
mena which can be traced to meteorites in all parts of space. 
‘In spite of the difficulties which attend the observations neces- 
sary to determine the velocity of meteors entering our atmosphere, 
many obseryations have been made, from which it may be 
gathered that the velocity is rarely under ten miles a second or 
over 40 or 50. It is known that the velocities of some meteor- 
swarms are very different from those of others. Professor Newton, 
our highest authority on this subject, is prepared to consider that 
the average velocity may be taken to be 30 miles a second.” 
Thus meteorites are as far as we know the most universally dis- 
tributed bodies in space, ani may reasonably be expected to play 
no inconsiderable part in the economy of nature. We must 
remember, too, that as the whole solar system is in perpetual 
onward, as well as rotatory motion, the earth can never twice 
occupy the same space ; so it is fair to suppose that every part of 
infinite space is equally full of meteorites as that we have already 
passed through, 
The existence of enormous numbers of meteors pervading space 
being proved, their tendency to collect in swarms within which the 
tendency to collision will be greater than in the surrounding space 
may be taken for granted; what then would be the effect of such 
collisions. Here again, I will quote Lockyer’s own words: ‘The 
question of what must happen to the meteorites themselves in 
consequence of this system of collisions is worth going into 
thoroughly. 
‘As 80 miles per second is a very frequent value obtained for 
the velocity of meteorites when they enter our atmosphere, it is 
possible to compare temperatures brought about by collisions with 
those produced by passage through our atmosphere. Two masses 
of meteoric iron meeting each other in space would probably, if 
moving with a certain velocity, be formed into a pasty conjoined 
mass, and this process might go on until an iron of large dimen- 
sions was formed, and the various meteorites thus welded together 
would present in time a very fragmentary appearance. While 
irons were thus increasing in size, collisions with smaller 
meteorites would be attended with very local increases of tem- 
perature, perhaps sufficient to volatilize the surface or allow it to 
be indented, and in this manner the well-known ‘thumb marks”’ 
receive explanation. 
«These operations of nature might go on either in free space, or 
in the head of a comet, or in meteor-swarms. They probably 
cause the appearance of the so-called new stars, and in these 
various circumstances the rate of subsequent cooling would. of 
