Reviews — Lowne's Philosophy of Evolution. 279 



of the surface, together with its shrinkage on contraction, gave rise 

 to the empty cracks already mentioned as here and there traversing 

 the plains. 



Such, briefly sketched, is the origin I venture to attribute to the 

 leading features of the moon's visible disc.^ It does not differ very 

 greatly from the view propounded by MM. Nasmyth and Carpenter, 

 except as maintaining the explosive character of the chief phenomena 

 — bringing them therefore nearer to the analogy of terrestrial vul- 

 canicity. The further progress of consolidation towards the interior 

 seems not to have affected the outer crust, either by that tangential 

 pressure to which some geologists attribute the crumpling of the 

 solidified surface of our globe, or that subsidence of the fractured 

 shell upon a shrinking nucleus, which Mr. Mallet considers to pro- 

 duce, by the conversion of its gravitating force into heat, terrestrial 

 volcanic energy. What contraction may have taken place in the 

 subcortical matter of the moon since the external features I have 

 described were stereotyped on its surface probably satisfied itself 

 by the production of rents, flaws, or cavities in the interior, as 

 often occurs in the cooling of large balls or cylinders of cast iron. 

 It is even possible to imagine that, if any water or atmosphere 

 originally existed upon the moon, it may have been absorbed through 

 the cracks described above into these interior hollows. At all events, 

 no traces appear on the surface of our satellite of further movement 

 or change, whether external or internal, since the incalculably re- 

 mote epoch when she assumed her present form and features. In 

 this belief we may address her as Byron addressed the ocean — 



Time writes no wrinkles on thy ' silver ' brow ; 



Such as Creation's dawn beheld, thou roUest now. 



G. PouLETT Soaops. 



II. — The Philosophy of Evolution.*^ 



SINCE 1859, when the Origin of Species appeared, the doctrine of 

 Evolution has permeated into almost every department of human 

 knowledge ; changing the ways of thought of the world. Like a 



1 A very simple experiment will illustrate to some extent the process to which I 

 ascribe the formation of the lunar craters. If powdered Parian cement or plaster of 

 Paris, mixed with water, of the depth of about half an inch, be placed in a common 

 frying-pan on a hot stove, large bubbles will rise upon its surface, and in a short time 

 several vent-holes will establish themselves, by which the steam generated throughout 

 the mass will escape with some violence; the lateral expansion of the escaping vapour 

 forcing up the half-liquid matter into a circular wall round each vent. Soon the 

 number of vents increases, the whole surface being covered with them. But the first 

 formed are the largest, those later formed diminishing in size, and no two disturbing 

 or interfering with one another. As the plaster dries and hardens, cracks establish 

 themselves. And in the end the crowd of small craters, unequal in size, and not 

 interfering with each other, produces a surface bearing a striking resemblance to 

 portions of the moon's face. If such a surface were supposed to be pressed down- 

 wards upon a still liquid substratum, so as to force up some of this through the 

 open vent-holes and cracks, to flood the surface more or less, and consolidate there 

 under the same circumstances as the original mutter, the resemblance would be still 

 closer, leading to the belief that the moon's surface owes its characteristic features to 

 some similarly rapid ebullition of a quickly-hardening semi-liquid matter. 



2 The Philosophy of Evolution (an Actonian Prize Essay). By B. Thompson 

 LowNE, M.K.O.S., E.L.S. 8vo. pp. 159. (London : Van Voorst.) 



