18411882] ICE-ACTION l6l 



about the drift formation near Rio. There is a sad want of Letter 508 

 details. Thus he never mentions whether any of the blocks 

 are angular, nor whether the embedded rounded boulders, 

 which cannot all be disintegrated, are scored. Yet how 

 can so experienced an observer as A. be deceived about 

 lateral and terminal moraines ? If there really were glaciers 

 in the Ceara Mountains, it seems to me one of the most 

 important facts in the history of the inorganic and organic 

 world ever observed. Whether true or not, it will be widely 

 believed, and until finally decided will greatly interfere with 

 future progress on many points. I have made these remarks 

 in the hope that you will coincide. If so, do you think it 

 would be possible to persuade some known man, such as 

 Ramsay, or, what would be far better, some two men, to go 

 out for a summer trip, which would be in many respects 

 delightful, for the sole object of observing these phenomena 

 in the Ceara Mountains, and if possible also near Rio? I 

 would gladly put my name down for 50 in aid of the 

 expense of travelling. Do turn this over in your mind. I 

 am so very sorry not to have seen you this summer, but for 

 the last three weeks I have been good for nothing, and have 

 had to stop almost all work. I hope we may meet in the 

 autumn. 



To James Croll. 1 Letter 509 



Down, Nov. 24th, 1868. 



I have read with the greatest interest the last paper which 

 you have kindly sent me. 2 If we are to admit that all the 



1 James Croll (1821-90) was born at Little Whitefield, in Perthshire. 

 After a short time passed in the village school, he was apprenticed as a 

 wheelwright, but lack of strength compelled him to seek less arduous 

 employment, and he became agent to an insurance company. In 1859 

 he was appointed keeper in the Andersonian University and Museum, 

 Glasgow. His first contribution to science was published in the Philo- 

 sophical Magazine for 1 86 1, and this was followed in 1864 by the essay 

 " On the Physical Cause of the Change of Climate during the Glacial 

 Period." From 1867 to 1881 he held an appointment in the department 

 of the Geological Survey in Edinburgh. In 1876 Croll was elected a 

 Fellow of the Royal Society. His last work, The Philosophical Basis of 

 Evolution, was published in the year of his death. (Nature, Vol. XLIII., 

 p. 180, 1891.) 



Croll discussed the power of icebergs as grinding and striating 

 agents in the latter part of a paper (" On Geological Time, and the 



VOL. II. 1 1 



