124 Xotices of Books. [January 



drenches," a " sphragidonychangocometical fellow," "geoplaty 

 logical lectures." 



The Orbs Around Us : A Series of Familiar Essays on the Moon 

 and Planets, Meteors and Comets, Suns and Coloured Pairs 

 of Suns. By Richard A. Proctor, B.A. (Camb.), Hon. 

 Sec. R.A.S., Author of "The Sun," " Other Worlds than 

 Ours," &c. London : Longmans and Co. 1872. 

 The well-known author of the interesting essay on " The Sun " 

 has become even still more popular by the publication of subse- 

 quent works upon the planetary system. But he has looked 

 back upon his v.ork, and found that the series of descriptions of 

 " Other Worlds than Ours " might, in his estimation, be made 

 to embrace a larger class of readers, if there were appended an 

 introduction or explanation. Careful not to explain too much, 

 Mr. Proctor has supplemented the work just now mentioned 

 with the one before us, on " The Orbs Around us." We will 

 state its salient points. The first essay is intended to elucidate 

 the mysteries of the spectroscope for those who have but a very 

 slight appreciation of the details of this mode of research. The 

 succeeding essays, on the subject of the plurality of worlds, are 

 especially interesting ; but even these are exceeded by that 

 entitled " The Rosse Telescope Set to New Work." The value 

 of the work, however, centres in the first essay, because its com- 

 prehension includes the capability of progress into more intricate 

 branches of the science of spectral analysis. Mr. Proctor's 

 mission is pre-eminently that of a great teacher of scientific 

 first principles ; and his books should be read by all who desire 

 to grasp, if not the detail, at least the liberal ideas of astrono- 

 mical science. There is no science whose views are so extended, 

 and we may be pardoned if we say that there are few so qualified 

 to impart a knowledge of these views as Mr. Proctor. 



The Strength of Materials and Structures. By John Anderson, 

 C.E., LL.D., F.R.S.E. London: Longmans and Co. 1872. 

 This treatise is one of the series of the Text-Books of Science 

 now in course of publication by Messrs. Longmans. It is divided 

 into two distinct parts. The first part treats of the natural 

 properties of various materials employed in construction, as far 

 as these qualities and characteristics are of importance to the 

 engineer. In this way the leading peculiarities of cast-iron and 

 wrought-iron, steel, copper, alloys, timber, &c, are described. 

 The student, in the second division of the work, is instructed 

 how to combine materials so as to obtain maximum strength at 

 a minimum of cost and weight. 

 The work is fully equal to its predecessors, and is characterised 



