« AnteriorContinuar »
June 17.—Being far in the ice, we only found a slight increase.
June 18.—A second sounding, 50 fathoms deeper than yesterday, when sailing among large pieces of floe-ice, gave an increasing temperature up to 48° F.
June 19.—To-day we had an increase of 7° above the surface temperature at 250 fathoms deep, although but 10 miles distant from yesterday's soundings; but the ice was more open : probably evaporation occurred here, owing to the surface not being so closely covered with ice.
June 20.—The first sounding shows the water to be coldest at the ice-foot; the second and third
the increasing temperature, which, as we were somewhat more closely packed in the ice, increased more quickly, and 39° F. is obtained at 150 fathoms deep.
June 22.—Here we were more closely packed. The surface was a degree colder than yesterday, and the water at the ice-foot had also gone down half a degree; but the warm stream below was the same. If we had had time to sound at greater depths, the temperature of the water would in all probability have been found still on the increase.
June 27.-In this case we have the warm current clearly defined at 250 fathoms depth, being kept below
by the lighter ice-water, which is nearly fresh, and of less specific gravity.
July 1.-We were clear of the ice, and had a lower temperature than before obtained. If the flow of warm water came from the south, the surface-temperature would have been greater than any temperature as yet obtained, because of the absence of ice.
July 6.—This observation shows a gradual increase as far down as 200 fathoms. We were well in the ice, and were prevented from continuing our sounding operations. Little evaporation has taken place, owing to the closeness of the ice and the gradual increase of the temperature, with one exception, which occurred on the 18th of June, when a temperature of 48° was obtained, -showing that the temperatures are materially affected by local causes, the closeness of the pack or the opening of the ice allowing evaporation to take place.
July 7.--Here, where the ice is close, there is a great difference between the surface temperature and that at the ice-foot. We pulled up a very beautiful description of star-fish (figured on the opposite page), which would not be likely to inhabit this warm current were it of volcanic origin.
July 10.—The crew being required elsewhere, we could not continue our sounding experiments. The
sounding shows a decrease of temperature, owing to the ice-water.
July 12.—This remarkable sounding was carefully
registered, specially by my friend, who saw the index before it was immersed, and immediately on its coming up.
This shows a gradual increase of temperature towards the north, proving the current to come from the north ; and its temperature being above that of the Gulf Stream, where it disperses itself, is a proof it is in no way connected with it.
The thermometer has since been examined by Mr.
L. P. Casella, who certifies that it “has been tested in the hydraulic press, as well as carefully compared with my standard, and found correct in every way, no change whatever having taken place in the instrument.”
Temperatures taken by Capt. David Grey, of the Eclipse whaler :
April 13, 15, 20.—When these three soundings were taken the ship was frozen in the pack; still there is a slight increase of temperature at the lowest depth.