314 The Past History of our Moon. [July, 
Moreover, around the orifice, the matter outflowing as the 
crust continued to contract would form a raised wall. Until 
the time came when the liauid nucleus began to contract 
more rapidly than the crust, the large crateriform orifice 
delivered of another). Accordingly I have never, on the one hand, found occasion 
—to the best of my recollection—to claim a disputed priority; nor, on the 
other, have I ever been unwilling to abandon a theory which I have formerly 
maintained on insufficient grounds. (I need only point to my article on 
“Mars,” in the “ Quarterly Journal of Science,’ for April, 1873, as an illus- 
trative instance, since I there not only abandon a theory I had once regarded 
with favour, but advocate carefully the theory advanced against it.) But the 
present instance is a somewhat peculiar one. In the “ Saturday Review ” for 
March 28th there is a paper which discusses lunar phenomena with consider- 
able acumen. Of course there is the giant-making process which in the 
‘‘Saturday Review” always precedes the process of giant-killing. The 
work of Messrs. Nasmyth and Carpenter is very warmly praised as a pre- 
liminary to the annihilation of their fundamental hypothesis. ‘* We honour,” 
says the condescending reviewer, ‘‘the courage which is daunted by no diffi- - 
culty, and we feel that the authors were bound to make their theory a complete 
one; but we should have not the less felt bound to point out the glaring 
absurdities of this hypothesis had not the more than diffident tone in which 
the authors themselves speak of it rendered such a proceeding unnecessary.” 
I am treated somewhat differently. A theory which I touched on first in these 
pages—the theory, namely, that some of the lunar markings on the moon’s 
surface may have been due to meteoric downfalls in the long past ages 
when that surface was plastic, and meteor flights were more important than now 
—is described as one which ‘‘ Mr. Proctor would have us believe,” although I 
said in so many words ‘‘that I should certainly not care to maintain that as 
the true theory ;”’ and is then summarily dismissed as a facetia. But while I 
am thus credited with insistance on a theory which I merely sketched as one 
not to be altogether overlooked in discussing peculiarities as yet not satisfac- 
torily interpreted, the reviewer wholly omits to mention that much earlier in 
my book I had advocated, in a much more definite manner, a view closely re- 
sembling (so far as it relates to the large craters) that which he himself advances 
as preferable to Nasmyth’s. I quote in full the passage in which I indicate 
and advocate, briefly but clearly, the theory urged above. At page 255 of my 
work on the “* Moon,” after describing the radiations from Tycho and other 
craters, I proceed—*‘ It appears to me impossible to refer these phenomena to 
any general cause but the reaction of the moon’s interior overcoming the ten- 
sion of the crust, and to this degree Nasmyth’s theory seems correct; but it 
appears manifest, also, that the crust cannot have been fractured in the ordi- 
nary sense of the word. Since, however, it results from Mallet’s investigations 
that the tension of the crust is called into play in the earlier stages of con- 
traction, and its power to resist contraction in the later stages,—in other words, 
since the crust at first contracts faster than the nucleus, and afterwards not so 
fast as the nucleus,—we may assume that the radiating systems were formed 
in so early an era that the crust was plastic. And it seems reasonable to con- 
clude that the outflowing matter would retain its liquid condition long enough 
(the crust itself being intensely hot) to spread widely,—a circumstance which 
would account at once for the breadth of many of the rays, and for the restora- 
tion of level to such a degree that no shadows are thrown. It appears 
probable, also, that not only (which is manifest) were the craters formed later 
which are seen around and upon the radiations, but that the central crater 
itself acquired its actual form long after the epoch when the rays were formed.” 
It will be manifest that the method here indicated as that by which the central 
crater acquired its actual form long after the rays had been formed, could only 
be that which the reviewer has indicated in the following passage :—‘t Assuming 
that the moon was once covered by a crust of rock, under a portion of which 
