W. WHITAEER ON SOME BORINGS IN KENT. 33 



The only other instances of a like occurrence that I have heard 

 of come from America. Mr. G. E. Broadhead has recorded that "in 

 boring to the depth of 833 feet, the drill was often observed to be 

 highly magnetized, but after that depth no further influence was 

 observed"*; and in a " Eeport on the Artesian Wells of Denver," 

 which forms the chief paper in the first volume published by the 

 new local Society, Mr. F. F. Chisholm says, " Upon the subject of 

 the so-called magnetic water, it is scarcely necessary to say that 

 water cannot be magnetic. The magnetism observed is located in 

 the casings, and is due to the magnetizing of the steel drill by fric- 

 tion and pounding, and this magnetism is communicated to the casing- 

 during the passage of the drill when lifted and lowered " f. 



4. Frindshury. Chattenden Barracks, North of Ujpnor. 1885. 



Communicated by Col. E. Hawthorne, R.E. and Mr. H. G. Lyons, 

 E.E. 



127 feet above Ordnance Datum. 



Shaft and cjdinders about 200 feet, the rest bored. 



Water from the three greenish sands (down to 123, 129|, and 

 146 feet respectively) was ferruginous. Water rises to about 114 

 feet from the surface, and, after pumping two hours, at the rate of 

 5000 gallons an hour, could not be lowered below about 170 feet. 



Thickness Depth 



in feet. in feet. 



London Clay, J brownish clay 16^ 16^ 



101 ft -^ Blue clay 75^ 92 



Aui It. 1^ Greenish sand and blue olay 9 101 



Oldhaven Beds. Gravel with chalk [? white flint pebbles] 



andsheUs 7^ 108| 



/'Fine sharp sand, with water 6^ 115 



Green sand 3 118 



Greenish sand 5 123 



Shells closely packed in blue clay 5 128 



Hard black shale 1 129 



Fine green sand | 129f 



Fine white sand 7 ISGf 



Greenish sand, wet, and blowing from 



under cylinder 10 145| 



Fine sand, almost on the move with 



water 20^ 167^ 



Blue clay, sand, and pebbles 1 108^ 



Thanet Beds, j Green sand 16| 184^ 



121|ft. 1 Blue sandy loam 105^ 290 



Chalk 493 783 



Gault (bluish-grey clay) 320 1103 



In all likelihood there is some mistake in classifying so great a 

 thickness of beds as Gault. It is not unusual for the clayey lower 

 part of the Chalk to be so classed ; and, as we have no reason to 

 expect any thinning of the Chalk, but on the contrary may count 



* Trans. Ac. Sci. St. Louis, vol. iii. p. 221. 

 t Proc. Colorado Sci. Soc. vol. i. p. 86 (1885). 

 Q .J. G. S. No. 165. D 



Woolwich Beds, 

 69| ft. 



