90 NATURAL SCIENCE. August. 



Museum ; and the works of Conybeare and Phillips, of De la Beche, 

 and Lyell, became his text-books. 



Entering the field of geology, as he tells us, for relaxation from 

 the cares of commercial life, he had in his early years only such time 

 as could be snatched from business at intervals, and chiefly on Satur- 

 days and Sundays. Fortunately his duties led him into various 

 parts of the country, and every opportunity was taken of making 

 acquaintance with the physical features and structure of the districts 

 he visited. It is, however, wonderful to find how much he achieved, 

 how early he had mastered the principles of geology, and how sound 

 were his interpretations of facts. 



His holidays during the years 1831 to 1833 were for the most part 

 spent in the region of Coalbrook Dale, and the results of his researches 

 were communicated to the Geological Society of London in 1834 and 

 1836. This work was published in full in the Transactions of the 

 Society, and looking at it now it may be regarded as a model of what 

 a memoir should be on such a subject as the coal-field and its asso- 

 ciated strata. The Silurian and Carboniferous rocks, the New Red 

 Sandstone, the igneous rocks and the drifts were all duly described, 

 and what is more remarkable, considering the youth of the author, the 

 superficial extent of the various rocks was shown on a map of the 

 scale of one inch to a mile, in a manner differing in no very important 

 particulars from the subsequently published map of the Geological 

 Survey. The structure of the area and its faults were carefully de- 

 picted, while the organic remains which Prestwich had obtained were 

 described with the aid of his friend John Morris. So highly indeed 

 would we speak of this work, that had the author done nothing sub- 

 sequently, we believe it would have entitled him to a permanent place 

 on the roll of those geologists who have rendered distinguished 

 service. 



In 1835 another paper was read by Prestwich before the Geo- 

 logical Society, on the ichthyolites of Gamrie in Banffshire, and this 

 was his first published work. In 1837 he supplemented it with obser- 

 vations on the drift deposits, including those of Blackpots, and he 

 noted the existence of a raised beach. 



These early studies give a good idea of the bent of his mind, his 

 attention being given to stratigraphical geology and to the physical 

 conditions under which strata were accumulated. In later years he 

 turned again to the Coal-measures in other regions, especially in 

 Somerset, and to their possible underground range in the south- 

 eastern counties, while the subjects of drifts and raised beaches 

 gained eventually more and more of his attention. 



Prestwich was elected a Fellow of the Geological Society in 

 1833, when Greenough was president ; and he first became a Member 

 of Council in 1846, when Murchison was president and Sedgwick, 

 Buckland, Fitton, Lyell, De la Beche, and others were his associates. 



He had now for some years been particularly occupied in what 



