part 1] ANNIVERSARY ADDRESS OF THE PRESIDENT. lix 



Heim in the Alps, and showed that they were those of the basal 

 wreck of a mountain-range. The scheme foreshadowed by this 

 paper was cut shoi't by severe ilhiess, from wliich he never re- 

 covered sufficiently to regain all his former vigour and endurance. 

 But in a few short notes he indicated some of the further 

 points that he had reached, including a description of the main 

 results of crust-creep, such as the formation of mylonites and 

 augen-schists, and an outline of the theory of dynamo-meta- 

 morphism to which he had been led. 



Perhaps the main effect on his own mind which resulted from 

 both the Uj^land and the Highland work was an appreciation of 

 the importance in geological history and tectonics of tangential 

 stress in the earth-crust. This was the key-note of his famous 

 Edinburgh address in 1S92, and was again referred to m his 

 Presidential Address to this Society, while the geographical bearing 

 of his 'fold-theory' was touched upon in a paper to the Poyal 

 (xeographical Societ}" and its time-relations in a lecture to the 

 Geologists' Association. 



While at Birmingham La])worth devoted mucli time to the 

 geolog}^ of Middle Britain, from Leicestershire to Merionethshire, 

 giving most of his energies to the older rocks. He ]:)roved the 

 existence of pre-Cambrian rocks at Nuneaton and the Lickey Hills, 

 and enlarged our knowledge as to the nature of the Uriconian 

 rocks of several Shropshire areas. He mapped the Longm3'nd, 

 made certain that it was of pre-Cambrian age, and divided the 

 succession into two conformable series, the lower of which he 

 paralleled with the rocks of Charnwood Forest and the higher 

 with the Torridon Sandstone. He proved that the Midland 

 Quartzites, like those of the Highlands, were Cambi'ian, and passed 

 ■up conformably into grits and sandstones, in which he found and 

 described Olenellus in Shropshire and the Hyolithus Limestone at 

 Nuneaton, thus proving the existence of Lower Cambrian rocks 

 in England. With Dr. Stacey Wilson he mapped the Lower and 

 Middle Cambrian rocks of the Harlech country. He outlined the 

 position of the Middle and Upper Cambrian shales at Stockingford. 

 and found the first fossils obtained from them. In Shropshire he 

 brought the Ordovician rocks into order, and compared them with 

 those of other regions. He enlarged our knowledge of the Coal- 

 Measures, and studied the question of the "• concealed coalfields,' 

 placing his knowledge at the disposal of the Royal Coal Commission 

 ■of 1902-1905. He indicated the possibility that the constituents 



