S54 



THE AZOIC SYSTEM AND ITS SUBBIYISIONS. 



workers in, geology or mineralogy, but also that he, at that time, liad^no 

 books relating to these subjects, although ho was then thirty^hrcc years 



of age.* 



In 1833 he appears to have begun his mineralogical and geological 

 work in an amateurish way; and later to have undertaken to lay down 

 the geology of the "South Welsh Coal Basni " on the maps of the Ord- 

 nance Survey. -A description of the geological map thus made consti- 

 tuted his first scientific paper, which was readf in 1837, at which time 



he was thirty-nine years of age. 



Logan gave up his business in Wales in 1840, proceeded to Canada ; 

 and, in 1841, visited the coal-fields of Nova Scotia and Pennsylvania. 

 At the time of his appointment as Director of the Canadian Survey, in 

 1842, the only scientific papers ho had read before any scientific body 

 (only one of which had been published) were devoted to questions 

 relating to the geology of coal; and in their recommendations of him 

 for the directorship 4?e la Bcche, Murchison, Sedgwick, and Buckland 

 placed all their emphasis on his skill as a geological surveyor of coal- 

 fields, t 



It can thus be seen that Logan, who was forty-four years old, had 



reached an age when most men's ideas and methods are fixed, the re- 

 mainder of their lives being spent in developing them. He was purely 

 a stratigraphical geologist, having had experience only in the study of 

 the well-marked stratified formations. Having then and over after "only 

 a limited knowledge of chemistry, mineralogy, and palaeontology," § and, 

 so far as we can learn, no acquaintance with crystalline and eruptive 

 rocks, beyond that acquired in the examination of some dikes in the coal 

 measures, Logan was set at work in a coimtry in which he was brought 

 face to face with some of the most difiicult problems with which a 



problems which demanded for their 

 soluti^on a training entirely diffcrcTit from that which he had. Now at 



geologist has ever had to cope 



the period when Logan began his stndy of geology, and during mucb of 

 the time when he was the head of the Canadian Survey, the rival theories 

 of Werner and Ilutton were yet bones of contention, in a disguised form, 

 while Lyell's publications were exerting a great influence. If we turn 

 to Logan's early reports on the Canadian geology it will be seen that 

 in the study of the older crystalline rocks he follows Lycll implicitly. 



* HarringtoTrs Life of Logan, 1883, p. 50. 

 t rroo, Efit. Assoc, 1837, YIL (sec), 83-85. 

 % Ilaniiigtoii's Life of Logau, pp. 126-132, 

 § Ibid., p. 397. 



