334 OhitKciry— Thomas Mellard Reade. 



article was brouglit before the Liverpool Geological Society in 1871 and 

 published in 1872, while the main facts and conclusions were printed 

 in advance in the Geological Magazine for March, 1872. The full 

 memoir, illustrated by colour-printed maps and sections, was a model of 

 carefully recorded observations ; and the author was enabled to make 

 out the succession of changes which affected the region subsequent to 

 the formation of the Boulder-clay. In particular he called attention 

 to the marine Formby and Leasowe Beds which occur between the 

 Inferior and Superior Peat and Forest Beds. 



In 1873 he gave an account of the Buried Valley of the Mersey, 

 and predicted that the tunnel which it was proposed to make beneath 

 the river would intersect a gully filled with Boulder-clay. This was 

 verified on the completion of the tunnel in 1885. 



The Drift beds of the North-West of England and North Wales 

 formed the subject of two papers brought before the Geological Society 

 in 1873 and 1882, in which he maintained the glacio-marine origin of 

 the Boulder-clay of the lower-levels, regarding as true Till, formed under 

 or in front of the local glaciers, the Boulder-clay of the mountain 

 regions. 



He was elected President of the Liverpool Geological Society during 

 the Sessions 1875-7, and again on two subsequent occasions, 1884-6 

 and 1895-7. In the address published in 1877 he took as his subject 

 "Geological Time", giving tabulated calculations of the total solids 

 in solution removed annually from each rainfall area and group of 

 strata in England and "Wales. This essay with additional matter was 

 reprinted in 1879, in a little volume entitled CJiemical Denudation in 

 relation to Geological Time. It included also a paper on " Limestone 

 as an Index of Geological Time", read before the Royal Society in 

 1879. Calculating the amount of carbonate and sulphate of lime 

 carried away annually from the igneous rocks on the earth's surface, 

 and the thickness of deposit that would result therefrom, Mellard 

 Beade compared this with the assumed thickness of limestone in the 

 sedimentary crust of the earth, and estimated that a period of about 

 si.x hundred million years would be necessary for the entire series of 

 stratified formations. Although subsequent researches tend greatly to 

 lessen the estimates of geological time, he may justly be said to have 

 initiated this instructive line of inquiry. 



While he continued his researches on local geology he brought his 

 experience on the Drifts to bear on other regions in the north and 

 east of England, in Ireland and Scotland; and he gave much attention 

 to Tidal Action as a Geological Cause, to Pebble Bidges, the 

 Circulation of "Water in Sandstone, the Physiography of the Trias, 

 and other subjects. 



In 1886 he published his important and elaborately illustrated 

 volume. The Origin of Mountain Ranges considered experimentally, 

 structurally, dynamically, and in relation to their Geological History. 

 In it he brought forward the results of much original study and 

 experiment, dealing especially Avith the effects of underground 

 temperature on the expansion of rocks beneath thick accumulations 

 which prevented the escape of heat, and led to folding, buckling, 

 and uplift of the formations. He also for the first time pointed out 



