PHYSICAL GEOLOGY. 405 



gaged his attention, and for years he continued to 

 collect the materials, which he finally embodied in a 

 voluminous memoir, read in 1874 before the Royal 

 Society [87], wherein he tabulated all the recorded 

 observations of sea-temperatures from 1749 to 1868, 

 and discussed some of their geological bearings. 



Nor did the more active geological operations of the 

 sea escape his scrutiny. Thus he made a careful study 

 of the conditions which seemed to him to have led to 

 the formation of the well-known Chesil Bank. In the 

 account of this inquiry, which he communicated to the 

 Institute of Civil Engineers [89], he combined the 

 results of an investigation of the present action of the 

 tides and currents along the Dorsetshire coast with 

 an examination of the proofs of earlier geological 

 changes in that district. In this, as in so many of 

 his other papers, he was able to bring a wide geo- 

 logical experience towards the elucidation of the prob- 

 lems which he undertook to discuss. 



In England, and more especially in the south-eastern 

 counties, the geologist has but slender opportunity of 

 studying the underground operations with which his 

 science deals. In the year 1870 Prestwich spent some 

 time among the volcanic regions of Italy. The writer 

 of the present notice of his labours had the advantage 

 of accompanying him in some of his excursions around 

 Rome and Naples, and recalls with pleasure the keen 

 interest which the veteran geologist took in every 

 phenomenon in the volcanic history of those fascinating 

 districts. He especially remembers the exploration of 

 Vesuvius, the scrutiny of the crater-wall of Somma, and 

 the enthusiasm awakened by the evidence of profound 

 erosion in the gullies that descend from the crest of 

 Somma into the plain to the north an enthusiasm 



