168 



Messrs. Carpenter and Jeffreys on 



[Dec. 8, 



the following morning. We then ran out to a spot almost precisely iden- 

 tical with that which had been our starting-point on the previous day ; and 

 commenced, as before, by testing the rate and direction of the surface- 

 movement. Its rate proved rather slower, being 2*40 miles per hour, 

 instead of 2*88 ; and its direction was E. by N., instead of E. by S. | S. 

 Both differences seemed to be accounted for by the difference in the force 

 and direction of the wind ; which, having been W. by N. with a force of 

 4 on the previous day, was now W. \ S. with a force of only 2. The 

 " drag " was then lowered to a depth of 400 fathoms ; but our expectation 

 that it would there encounter a westerly (or outward) current sufficiently 

 strong to carry the boat in that direction in spite of the antagonistic move- 

 ment of the easterly (or inward) surface-current, was not verified on this 

 occasion ; for the boat slowly drifted in an E. -J- N. direction, its rate being 

 0*650 mile per hour. Whether this result should be taken to indicate a 

 stationary condition of the deep stratum, or a slight movement in either 

 direction (§ 39), could scarcely be affirmed with positiveness ; but from the 

 indication afforded by the Specific Gravity of the water taken up from this 

 depth (§ 34), it seemed probable that the general movement of this 

 stratum was at this time rather westerly, or in conformity with that which 

 we attributed to the intermediate stratum, though at a slower rate. — It will 

 be shown hereafter (§62) that a decisive proof of such a movement was 

 obtained on a subsequent occasion. 



43. Thinking it expedient to postpone the further prosecution of this 

 inquiry until our return voyage, — when we should be able to repeat our 

 experiments, not only at this narrow end of the Strait, but also at that 

 shallowest portion to the westward where the Strait opens out into the 

 Atlantic, — we put steam on before mid- day, and entered the basin of the 

 Mediterranean, directing our course in the first instance to the spot (Lat. 

 36° 0' N., Long. 4° 40' W.) at which the sample of bottom-water had been 

 obtained by Admiral Smyth, which, when analyzed by Dr. Wollaston, was 

 found to possess the extraordinary Specific Gravity of 1-1288, and to yield 

 a percentage of 17'3 of Salt *. As we were within sight of both shores, 

 and could distinguish several remarkable mountain-summits which were 

 accurately laid down on our Charts, the bearings of these enabled the situa- 

 tion of the Ship to be determined with great precision ; and Capt. Calver 

 undertook to place her within a mile of the point at which Admiral Smyth's 

 observation had been taken. Having reached this (Station 40) we took our 

 first Sounding in the Mediterranean ; and awaited the result with no little 

 interest. The depth proved to be 586 fathoms, or 84 fathoms less than 

 that given by Admiral Smyth's sounding ; but as the latter was not taken 

 on the improved method now adopted, and as its correctness may have not 

 improbably been affected by the strength of the easterly current which is 

 here very perceptible, the discrepancy can scarcely be considered as of any 

 real account as showing that the two points were otherwise than nearly 



* Phil. Trans, for 1829, p. 29; and Admiral Smyth's « Mediterranean,' pp. 128-130. 



