66 CARNEGIE INSTITUTION 



{^Prof. G. N. Darwin to Geo. F. Becker, Ju?te 26, 1902,1 



Newnham Grange, 



Cambridge, Kngi.and,/«;?^ ^d, 1002. 

 My Dear Sir : 



It is clear tliat there is a verj^ v^-ide scope for good work in geo- 

 physics iu all the directions which yon specify in your memoran- 

 dum, and, as I said to Mr. Walcott, the limitatiojis are set rather 

 by the men than by the subjects. 



I do, not know the procedure by which the Carnegie trustees will 

 allot the money to various projects. It maybe necessary to draw 

 lip a scheme, complete in all lines of research. Mistakes will in- 

 evitably be made, and all that can be done to avoid them is to take 

 great pains in drawing up the proposals. 



I believe, however, that the most efficient plan would be to make 

 the start in a humbler scale, but in such a wa}^ as will easil}' aliovv' 

 of expansion in various directions. This conception would only 

 be best if money will be forthcoming for expansions when they 

 shaJi be seen to be desirable atid feasil:>le. My reasons for sajdng 

 this is that a geoph^'-sical observatory'- and laboratory is a iiew thing, 

 and can not be planned with the same completeness as is possible in 

 the case of astronomy . 



Whatever line is taken it is very desirable that you should have 

 thorough knowledge of the methods pursued at Strassburg, Got- 

 tingen, the Italian and Japanese observatories. I would recom- 

 mend that 3-ou should learn what Milne is doing in the Isle of 

 Wight, and hear what he has to say as to equipment. I believe 

 that Urechert's great pendulum at Gottiugen is better than anj" 

 other instrviment of the kind for a fixed permanent observatory, 

 but it must have been so expensive as to be beyond the means of 

 almost any private person. 



I venture to suggest two researches v.-hich would,. I think, be of in- 

 terest. I should like to see made a study of earth tremors and deflec- 

 tions of the vertical deep down in mines. I conjecture that it would 

 be necessary to iartalltwo, or even three, instruments at the top and 

 bottom, and, perhaps, at an intermediate depth. If this matter has 

 been studied at all, at least ^t has been very imperfectly investi- 

 gated. Might it not perhaps throw some light on the broad yield- 

 ing of the solid earth ? 



The expense would no doubt be considerable, and the observer 

 must be a competent man who can make daily visits to the bottom.. 



