1870.] 



Deep-sea Researches. 



183 



the Ship having been determined by angles taken with the shore, the rate 

 of the surface-movement was tested as on former occasions, and was 

 found to be 1*277 mile per hour, its direction being E. \ S. The 

 " current-drag " was then sunk to 150 fathoms, the greatest depth at 

 which it was thought safe to use it ; and the boat from which it was 

 suspended moved E. | N. at the rate of 0*840 mile per hour. This 

 observation indicated a very considerable retardation in the rate of wflow, 

 but gave no evidence of an ow^flow. It did not, however, negative the 

 inference deducible from the Temperature, and still more from the Specific 

 Gravity, of the water beneath, that an outflow takes place in that lowest 

 stratum which we could not test by the " current- drag." 



68. We then steamed across the deep channel towards the Spanish 

 side ; and passing a bank of 45 fathoms which rises near its middle, we 

 sounded again at Station 66, about six miles to the northward of Station 

 65. The surface-temperature at 9 a.m. was here found to have risen to 

 69° ; and since not more than half this increase could be attributed, 

 according to our general experience, to the increase of direct solar radiation 

 at this period of the day, the cause of the additional elevation has to be 

 sought elsewhere (§ 78). The length of sounding-line run out was 147 

 fathoms ; but on attempting to reel it in, the lead was found to have fixed 

 itself between rocks ; and all Capt. Calver's skill in the management of 

 his ship proved inadequate to free it. As we were thus anchored by our 

 sounding-line, it was requisite to set ourselves free, by putting a breaking 

 strain upon it ; and we thus lost, with the lead, one of our Water-bottles, 

 and a pair of Thermometers, one of which was specially valued by us as 

 having been used throughout the 'Porcupine' Expedition of 1869, in 

 which the Temperature-soundings had proved of peculiar importance. The 

 "current-drag" was here letdown to 100 fathoms; and the boat from 

 which it was suspended moved along in the direction of the surface- 

 current, and at the rate of 1*280 mile per hour, which was almost precisely 

 that of the surface-current in the previous observation. 



69. Deeming it important to obtain the Temperature and Specific 

 Gravity of the bottom-water on the Spanish side of the deeper portion of 

 the channel, we slightly shifted our ground, and again let down our lead, 

 with Thermometers and Water-bottle, at Station 67, where the depth 

 proved to be 188 fathoms. On beginning to reel in the line, we found the 

 lead to have anchored as before, and for some time feared that we should 

 sustain a second loss of the Water-bottle and Thermometers attached to it. 

 The means taken by Capt. Calver for its extrication, however, proved on 

 this occasion successful ; and we had the satisfaction of seeing the whole 

 apparatus safely brought up, — the lead bearing evident marks of having 

 been jammed between rocks and then violently strained. The Temperature 

 of the bottom proved to be 55°*3, that of the surface being 73° ; and the 

 Specific Gravity of the bottom-water was 1028*1, that of the surface 

 being 1026 8. Here again, therefore, the evidence afforded by the Tern- 



