Ohituarij — Thomas Mellard Rcade. 335 



that at a certain depth in a cooling solid globe there must be a ' level- 

 of-no-strain ', a conception which has been generally recognized as of 

 great significance in indicating that the disturbances are likely to be 

 confined to a comparatively thin crust. 



In recognition of this work and of his other contributions to 

 geological science the Murchison Medal was awarded to him by the 

 Council of the Geological Society in 1896, when Dr. Henry Woodward 

 was President. 



In 1903 Mellard lleade published The Evolution of Earth Structure, 

 with a theory of geomorphic changea. In this work he explained the 

 geographic relief of the globe as due (1) to differential alterations of 

 volume in large sections, which take place with extreme slowness and, 

 being deep-seated, upheave or depress portions of the earth's crust 

 without wrinkling it; and (2) to the tangential creep and ridging up 

 arising from the heating of sediments and variations of temperature, 

 and consequent expansion, within the earth's crust brought about by 

 sedimentary deposition. He further illustrated the subject with the 

 results of many experiments on the folding and fracture of materials, 

 and reproduced the account of investigations made in conjunction with 

 Mr. Philip Holland on slaty cleavage. He also republished some 

 essays on denudation, the permanence of oceans and continents, and 

 other subjects bearing on the question of the structure of the earth and 

 the origin of its main features. 



During the last ten years Mr. lleade worked a good deal with 

 Mr. Philip Holland, F.I.C., and together they published papers 

 dealing with mechanical and chemical analyses of Ludlow rocks and 

 Old Eed Sandstone and Marl, and also with the subject of sands 

 and sediments, treating these latter materials stratigraphically, 

 microscopically, and chemically. From their observations the authors 

 were impressed with the great amount of micro-sediment met with, 

 such as the very fine powder of quartz which they termed quartz- 

 dust. They observed that clay and iron -oxides are present in the 

 clearest sea-water, and particles of carbonate of lime likewise occur, 

 held up by the clay and not in solution. Finally they pointed out 

 that the sea would carry about and distribute these micro-sediments, 

 and thus make important additions to oceanic deposits. 



The final paper by Mr. Mellard Keade, a short article on " The 

 Mechanics of Overthrusts ", was printed in the Geological Magazine 

 for February of the present year. 



Thus to the last he remained an indefatigable worker on dynamic 

 geology and on the architecture of the earth's crust, subjects to wliich 

 his professional experience advantageously and perhaps naturally led 

 him. The business of his life indeed afforded him many opportunities, 

 which he fully utilized, of seeing fresh sections of the strata, and it 

 inculcated those methods of precision which characterized his records 

 and experiments. 



A severe illness during infancy produced a certain amount of deafness 

 from which Mellard Reade suffered until the end of his days, and it 

 increased with advancing years. On this account he rarely attended 

 scientific- meetings other than those of the Liverpool Geological Society. 

 He printed two lists of his geological papers — 



