JS T otices respecting Keic Boohs. 227 



any moment, without the slightest probability of its being detected". 

 as an instance of physical change on the moon. Thus, for example, 

 if on the moon proportionately the same amount of yolcanic energy 

 were every year manifested in a similar manner to what occurs on 

 the earth, there is no reason whatever for supposing that it would 

 have been hitherto detected. "With the present condition of our 

 acquaintance with the topography of the lunar surface, in this 

 state, it is not in the slightest degree surprising that no definite 

 instance of volcanic energy on the moon has hitherto unmistakably 

 declared itself. Nor can this circumstance justify its being held 

 that selenological volcanic activity must have long ere this entirely 

 ceased to exist." As one of the instances in which there may be 

 great probability of physical change having taken place, Mr. JNTeison 

 gives the well-known case of Linne, which he treats with consider- 

 able impartiality, and shows that, so far as the evidence collected in 

 1867 and 1868 bears on the question, it is the difficulty of recon- 

 ciling Schroter's with Lohrmann's and Madder's drawings which 

 renders any conclusion as to a real change having taken place 

 unsatisfactory. For his treatment of this vexed question we must 

 refer the reader to the work itself, pp. 185-192. We may, how- 

 ever, remark that the whole matter turns upon the identification 

 of one or other of two of Schroter's spots with Linne ; on this 

 point the author says : — " Birt's view of the identity of g and Linne, 

 and of v with the small white spot known to exist south of it, 

 merits consideration ; for if this be correct, the weight laid upon 

 Schroter's drawings as showing that in his time Linne presented 

 the same appearance as now, rests on a misconception ; and with 

 the correction of this the entire fabric constructed to demonstrate 

 the absence of any change in Linne crumbles into ruin." 



The second and by far the largest portion of the work consists 

 of a description of the 513 named objects on the surface of the 

 moon, accompanied by twenty-two maps showing their localities. 

 This portion, there can be no doubt, must be found of great value 

 to the selenographer. It would, however, have contributed to easy 

 reference had each formation been preceded by a number, as in 

 Webb's book. The information contained in the description of 

 these objects supplies a want increasingly felt by every student of 

 the moon's surface. A chapter is added on selenographical formulae, 

 also tables of points of the first order, lunar elements, &c. 



Taking a general view of the work, it is one that brings before 

 the student nearly the whole of the known desiderata of seleno- 

 graphy, which, combined with the valuable information it contains, ■ 

 renders it a most important acquisition ; we notice, however, the 

 absence of one characteristic which might have been introduced 

 with advantage. Mr. Neisoti repeatedly urges the necessity of 

 certain features being subjected to a close and searching investiga- 

 tion ; a short chapter on the best method of conducting such 

 investigations would greatly contribute to guide observers who may 

 be just entering on the study of selenography ; and no one could 

 pen instructions of the kind so well as the author, whose success 

 both as regards this work and his future investigations we mo* t 

 sincerely desire. 



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