J PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [May 1904, 



perfect topographical geologist our science had." Those who have 

 travelled through the Carboniferous region of Pennsylvania, or 

 have studied the excellent detailed maps of it which the State 

 Surveys have published, will not wonder at the claim made by 

 Lesley that * topographical geology was born ' in that State ; nor 

 will they fail to note how easily and irresistibly Lesley was led 

 into that domain of geology where he became so pre-eminent a 

 master. The contours of the surface depend so directly and clearly 

 upon curvature and fracture of the terrestrial crust on the one hand, 

 and upon the results of erosion on the other, that in few tracts of 

 the earth's surface is this relationship so readily grasped, or appeals 

 so powerfully to the imagination. 



Before he was one-and-twenty Lesley had constructed his first 

 topographical and geological sketch-map, which earned the com- 

 mendation of Rogers * for the faithful and laborious manner in 

 which he had unfolded the geology of this occasionally complicated 

 zone of country.' His scientific career, however, was soon arrested 

 by the refusal of the State Legislature to grant any further appro- 

 priation for the continuance of the Survey, and by the consequent 

 disbanding of the staff of assistants. Thus thrown back upon himself, 

 the young geologist turned once more to the line of life which had 

 been originally marked out for him. His geological rambles among 

 the remote valleys of his native State had brought vividly before his 

 eyes the benighted condition of their inhabitants ; and now the idea 

 was revived that he should proceed with his theological studies, in 

 order to fit himself for the ministry and for eventually becoming a 

 missionary to these neglected people. He accordingly entered the 

 Theological Seminary at Princeton in 1841, and likewise proceeded 

 to his degree of A.M. at the University of Pennsylvania. While 

 working at Hebrew and theology, however, he found time, at 

 Rogers's request, and with much patience and skill, to put together 

 the mass of materials that had been gathered by the assistants for 

 the construction of a coloured topographical and geological map of 

 Pennsylvania. In this laborious task, as in all his subsequent 

 labours, the value of his early training in drawing became strikingly 

 conspicuous. 



Having passed through the theological training, and having 

 received his licence as a clergyman from the Presbytery of Phila- 

 delphia, he took a trip to Europe in 1844. Landing in Liverpool, 

 he first made a walking pilgrimage through England, and thereafter 

 another, with knapsack on back, through the west and south of 



