GEOLOGY. 311 



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derivable from the ordinary process ; but for really satisfactory re- 

 sults, far more accurate and conclusive processes need to be instituted. 



Two leading processes appeared to him as being applicable to these 

 determinations : First, the planting in particular positions of inquiry 

 in the ocean, from an attendant vessel, buoys with flags, kept in their 

 places by a resisting apparatus below the surface, which might be de- 

 nominated a current measurer, and determining, after a night's action, 

 for instance, the changes of their position from celestial observations. 

 Then, secondly, placing a small boat upon the water during a calm, 

 with the current apparatus for the determination of the relative set of 

 strata currents. The current measurer attached to, and suspended by, 

 a small wire run off a reel fixed in the bow of a boat, might be let 

 down to various depths in succession, with a register thermometer at- 

 tached at each new depth, when the motion of the boat and its direc- 

 tion, as shown by the position of a surface float or buoy, would after 

 but short intervals of time, indicate proximately the relative motion 

 of the surface water at the several depths of the resisting apparatus 

 below. 



At the conclusion of the above paper by Dr. Scoresby, Dr. Buist 

 exhibited and explained the construction of a new current measurer. 

 This instrument resembled a common weathercock turned upside 

 down, and which on being lowered by a wire to any depth, took the 

 direction of the current. It was furnished with a compass, the needle 

 of whic i was clamped at the proper time by a second wire, when a 

 bladed wheel like tnat of a patent log, or of a ventilator, was allowed 

 to revolve for a minute, and worked like a o-asmeter bv an endless 



* / 



screw into a toothed wheel, and when the whole was drawn up, it in- 

 dicated the direction and velocity of the current at any given depth. 



DEEP SEA SOUNDINGS. 



The following is an account of a remarkable deep sea sounding 

 made on the 30th of October, by H. M. Ship Herald, in the course of 

 a passage from Rio de Janeiro to the Cape of Good Hope, 36 49' 

 South Latitude, and 37 6' West Longitude. The sounding-line was 

 y 1 ^- of an inch in diameter, laid into one length, and weighing, when 

 dry, one pound for every hundred fathoms. Captain Denliam received 

 from Commodore McKeever, of the United States Navy, commanding 

 the Congress frigate, a present of 15,000 fathoms of this line, 10,000 

 fathoms on one reel, and 5000 on another ; and considers it to have 

 been admirably adapted for the purpose for which it was made and to 

 which it was applied. The plummet weighed 9 Ibs., and was 11.5 

 inches in length, and 1.7 inch in diameter. When 7706 fathoms had 

 run off the reel the sea-bottom was reached. Captain Denhain states 

 that Lieut. Hutcheson and himself, in separate boats, with their own 

 hands, drew the plummet up 50 fathoms several times, and after it had 

 renewed its descent, it stopped, on each occasion, abruptly at the 

 original mark to a fathom, and would not take another turn off the 

 reel. The velocity with which the line run out was as follows : 



