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July 31. At one P. M. the Start bore W. N. W. distant six leagues. August 1. The water appears luminous in the ship's wake.
2. The temperature of the water is taken at eight in the morning and at eight in the evening.
6. The water appears less luminous.
7. Formegas S. W. distant 32 degrees. St. Mary's S W. S. 33 leagues.
8. From this date the temperature of the water is taken at eight in the morning and at six in the evening.
10. Moonlight, which prevents the luminous appearance of the
12. Ditto. From this date the temperature of the air and water was taken at noon, as well as morning and evening
19. First saw gulf weed.
Again saw gulf weed.
24. The water appeared luminous in a small degree before the
29. No moon, yet very little light in the water.
33. Much gulf weed to-day.
September 1. Ditto.
2. A little more light in the water.
4. No gulf weed to-day. More light in the water
5. Some gulf weed again.
6. Little light in the water. A very hard thunder-gust in the
7. Little gulf weed.
8. More light in the water. Little gulf weed.
9. Little gulf weed. Little light in the water last evening. 10. Saw some beds of rock-weed; and we were surprised to observe the water six degrees colder by the thermometer than the preceding noon.
This day (10th) the thermometer still kept descending, and at five in the morning of the 11th, it was in water as low as 70, when we struck soundings. The same evening the pilot came on board, and we found our ship about five degrees of longitude a-head of the reckoning, which our captain accounted for by supposing our course to have been near the edge of the Gulf Stream, and thus an eddy-current always in our favor. By the distance we ran from September 9th, in the evening, till we struck soundings, we must have then been at the western edge of the Gulf Stream, and the change in the temperature of the
water was probably owing to our suddenly passing from that current into the waters of our own climate.
On the 14th of August the following experiment was made. The weather being perfectly calm, an empty bottle, corked very tight, was sent down 20 fathoms, and it was drawn up still empty. It was then sent down again 35 fathoms, when the weight of the water having forced in the cork, it was drawn up full; the water it contained was immediately tried by the thermometer, and found to be 70, which was six degrees colder than at the surface; the lead and bottle were visible, but not very distinctly so, at the depth of 12 fathoms; but, when only 7 fathoms deep, they were perfectly seen from the ship. This experiment was thus repeated September 11th, when we were in soundings of 18 fathoms. A keg was previously prepared with a valve at each end, one opening inward, the other outward; this was sent to the bottom in expectation that by the valves being both open when going down, and both shut when coming up, it would keep within it the water received at bottom. The upper valve performed its office well, but the under one did not shut quite close, so that much of the water was lost in hauling it up the ship's side. As the water in the keg's passage upwards could not enter at the top, it was concluded that what water remained in it was of that near the ground; and, on trying this by the thermometer, it was found to be at 58, which was 12 degrees colder than at the surface.
[This last Journal was obligingly kept for me by Mr. J. Williams, my fellow-passenger in the London Packet, who made all the experiments with great exactness.]*
* The chart given in this edition has been constructed with a view to give a more comprehensive idea of the course of the Gulf Stream. Volney very plausibly suggests, that the earth, deposited by the Gulf Stream southeast of Newfoundland, has formed the great banks; and that the accumulation there has given the stream a new or more eastwardly direction. This chart also serves to illustrate the long-received ideas of the progress of the shoals of fish. May not the glutinous matter seen on the water, and which all persons who have been across the line must have noticed, be another cause of the phenomena of fish shoals. May they not come in search of the food, which the matter seen on the water in such abundance affords? The writer of this note has observed, that, on entering the trade winds, the seamen have judged of the change of wind approaching by the direction of the bonetta and other fish, which pass in shoals in the South Atlantic and southeastern Seas, in a direction opposite to the wind; and when not opposite to the prevailing wind, they conclude a change to be at hand from the direction towards which the fish go. The appearance of luminous floating matter at night is often followed by shoals of fish; the spawn or gluten, which the writer has had taken up in a bucket, has been often found as large as two inches diameter, and frequently induced an opinion that it was a species of maritime cocoon or egg of an animal. Fragments of irregular shaped gluten have been also often seen. An inquiry into the