1865. 



( 753 ) 



NOTES AND CORRESPONDENCE. 



On the Probable Conditions {Past and Present) of the Lunar Surface. 

 ByT. Clifford Allbutt, M.A., M.B., Cantab. 



I lately took up the number of 

 your Journal, published in January 

 last, and in it I find a letter from 

 <• Mr. Nasmyth, in which he specu- 

 lates on the vast antiquity of the 

 lunar sm-face. By it I was re- 

 minded of a previous communication 

 by Mr. Nasmyth on a like subject, 

 which was accompanied by a most 

 admirable lithograph of a portion 

 of the lunar surface. As I read 

 these remarks certain speculations, 

 which I have long entertained, rose 

 in my mind, and I now offer them 

 to you for what they may be 

 worth. Mr. Nasmyth says in his 

 letter of January, that "the moon 

 in all reasonable probability never 

 possessed an atmosphere or water- 

 envelope." He said, also, in his 

 former communication (which I 

 find in your number for July, 1864) 

 that the moon is not necessarily 

 a " useless waste of extinct vol- 

 canoes," although it be "unfitted 

 for animal or vegetable existence 

 as known to us," &c. &c. In these 

 and in many similar places Mr. 

 Nasmyth does but speak as all 

 competent astronomers speak of 

 the moon, as being now a hideous 

 waste, airless, waterless, and life- 

 less ; and as having probably been 

 so always. Now, sir, I cannot but 

 take a view, which to some degree 

 differs from this. As regards the 

 present state of the moon, I am in 

 full agreement with Mr. Nasmyth 

 and other admirable observers whom 

 I trust far better than I trust my- 

 self. I differ with them in regard of 

 their inference as to the past states 

 of the moon. I may be allowed to 

 quote from Mr. Nasmyth's first 

 paper, the following line, " particles, 

 originally existing in a diffused con- 



dition, were by the action of gravi- 

 tation made to coalesce and so to 

 form a planet." It will be seen on 

 reference that he thus speaks in 

 explanation of certain volcanic phe- 

 nomena common to the moon and 

 to our own planet ; and that he 

 speculates on their common origin 

 and similar development. The con- 

 sequents which we find in the moon 

 being so far almost identical with 

 those which we find in the earth, 

 we are justified in expecting that 

 the antecedents were also identical, 

 or nearly so. 



I am glad to have this common 

 starting point, and these common 

 results, from which I may ask Mr. 

 Nasmyth to pass to a consideration 

 of transition states. 



Now, sir, no discoveries have in- 

 terested us more than those by 

 which we have learned that the 

 constituent elements of our own 

 planet correspond in great measure, 

 if not thoroughly, with those of 

 other heavenly bodies. These dis- 

 coveries justify a presumption that 

 the moon, which as a mass of mat- 

 ter lies adjacent to us (and has even 

 by some been supposed to have 

 been ejected or detached from our 

 own planetary mass at some early 

 period of consolidation), consists of 

 elements the same, or nearly the 

 same, as those of which the earth 

 consists. We should then further 

 presume that, if subject to like con- 

 ditions, the mass of the moon would 

 also tend to pass through stages of 

 existence corresponding to those of 

 the earth. Some of those condi- 

 tions, however, are widely different, 

 as, for instance, the relation of 

 volume to superficies, the power of 

 gravitation, and some others. Still 



