LETTERS TO J. W. JUDD 



photo-engraved copy of Percival's map of the trap-region. 

 It shows well the narrow features of the belt and their 

 relations. There are no broad streams exposed to view 

 over large surfaces: nothing but narrow linear outcrops, 

 with sandstone covering the eastern slope and underneath 

 the western front. I send you a copy of the photograph 

 from which Plate VII. in my August paper was taken. 

 The thinning of the trap sheet westward is only photo- 

 graphic error; for it keeps its thickness of two hun- 

 dred to two hundred and fifty feet quite to the edge of 

 the western columnar front, and moreover the upper sur- 

 face continues to rise westward to the edge. Since the 

 distance of outflow was not over five or six hundred 

 yards, this great thickness and the upward rise of surface 

 could not have been a fact unless the outflow mentioned 

 had been under cover of the sandstone. The views look 

 like a sub-aerial overflow; but had this been true, the 

 stream, it appears to me, would have flattened out to 

 half its thickness and less." 



DANA TO JOHN W. JUDD 



" NEW HAVEN, February 19, 1892. 



" Your kind letter and the photograph were received 

 at the close of last week and gave me great pleasure. It 

 is very gratifying to have the degree of personal know- 

 ledge of a friend which a photograph gives when this is 

 all that is within reach. 



" I have through life found great satisfaction in being 

 virtually an Englishman, and have rejoiced in, and won- 

 dered over, the grandeur and power of the British nation. 

 Your cordial recognition of our relationship is most 

 cordially reciprocated." 



VI 

 FROM OCCASIONAL CORRESPONDENTS 



The first two letters selected from occasional corre- 

 spondents are those which were written by the great 

 Swedish chemist, after he had received the first and (eight 



343 



