1904 - 5 .] Mr Romanes on the Formation of the Moon. 479 
It may finally be suggested that the sudden accession of large 
quantities of matter, such as that of a mare, to the moon’s surface, 
might slightly alter its balance, and cause it to turn a somewhat 
different face to the earth. The frequent occurrence of such 
changes would be in favour of its assuming the true form of 
equilibrium even although it has never been fluid ; and all in- 
fluences to which it has been subjected would have the same 
tendency. 
The writer has heard, since this paper was read, that former 
attempts have been made to illustrate the formation of lunar 
craters by firing bullets ; but he has heard of no former attempt 
to explain the whole formation of the moon’s mass as due to 
impacts of bodies which have always been part of the earth’s 
system, in the manner explained above. 
He wishes to state that he is greatly indebted to Mr Heath of 
the Royal Observatory for help of every kind in gaining informa- 
tion, and for the slides which were shown in illustration of this 
paper. 
( Issued separately March 30 , 1905 .) 
