190 APPENDIX. 



can in this way be roughly arranged in groups having a kind of order of date. From these 

 considerations the final induction was made by the comparison of the two series of groups ; there 

 were thus discovered some remarkable cases of apparent coincidence, the same individual 

 chains forming groups in the two categories. This striking fact was enunciated in the 

 theory that parallel mountain chains are of synchronous origin, and vice versa. Such a group 

 of parallel lines of elevation or of disturbance is what M. de Beaumont means by a system o> 

 mountains ; members of the same groups, according to his view, occurring often far apart, and 

 quite unconnected by any visible feature. 



The adoption of such views as those just indicated involves that of a world-wide force 

 affecting the whole earth simultaneously, and to the complete subordination of local or super- 

 ficial influences. The author accepted this necessity in the boldest manner, and framed a 

 theory of action commensurate with its demands. Upon the basis of a very generally received 

 opinion — the great internal heat of the earth — -he states the conditions that might fulfil the 

 supposed results. These conditions were, a fluid internal mass covered by a comparatively 

 thin solid crust. The gradual loss of temperature which the total mass would undergo must 

 be almost exclusively at the expense of the highly heated interior, and the consequent con- 

 traction would also be confined to the fluid matter in the interior. In order to adapt its 

 capacity to the diminished volume of its contents the spheroidal shell would become distorted, 

 producing tuberances {bossellements) of the surface. The tension thus produced would at 

 last result in rupture, and a new equilibrium would be established by the crushing of the 

 shell along the lines of fracture. He adduces mechanical laws to show that these tuberances 

 and lines of fracture would occur within a fuseau* 



Not content with giving a complete account of one single convulsion of the earth's crust 

 resulting in the formation of one system of mountains, M. de Beaumont goes on to show, and 

 lie illustrates the idea by an appeal to facts, that successive convulsions must so occur that 

 these characteristic directions should group themselves in pentagonal symmetry. For this 

 complete generalization he again appeals to geometrical and mechanical principles. He states 

 that in such n splitting up of the sphere the pentagonal form gives a maximum of result 

 with least effort. Consistent with the postulates on which he starts, our author adopts in their 

 fullest sense the doctrines of the supporters of geological catastrophes. 



In reading M. de Beaumont's work it is impossible not to be captivated by the beautiful 

 order he establishes out of an apparent chaos. Even with a full knowledge of how inexact 

 the facts must be upon which he proceeded, and of how erroneous many of his assumptions 

 have been proved to be, one cannot help giving way to an unscientific feeling of hope th:it 

 in the main he may be right. As the author himself admits (p. 1259), all that is essential in 

 the theory- seems to be compatible with other conditions than those adopted by him, such as 

 with a solid sphere and comparatively cool interior, or with a gradual action instead of a 

 sudden catastrophe, the one unalterable feature being permanent surface temperature and 

 reduction of internal heat. Our study of the Himalayas may have added fresh evidence against 



* A segment of a sphere contained between two great, conterminous semi-circles of the sphere. He gives 

 (p. 1255) a probable liirit of 20° for the width of the fuseau within which the same system of disturbance can occur. 

 The author further insists (p. 674) uyou the probable irregularity in direction of fissures occurring near the points 

 of the fuseau, and hence he infers the probable difference in age of ranges situated at the antipodes one of the 

 other and parallel to the same great circle of reference, (tlie circle bisecting the fuseau longitudinally): such ranges 

 probably belong to different overlapping fujeaux. 



