In other portions of the world recent experiments have shown that a system of revolution is going on in the separate basins into which the ocean is divided; where the land bounds any expanse of water in several directions, the tides and currents circulate around its borders, leaving the central space comparatively or perfectly free from their action. This notion was perhaps first distinctly enunciated by Professor Whewell, as to the North Sea tides, and confirmed by Capt. Hewett. As we shall have occasion to advert to presently, a similar basin is to be found, though on a very much more magnificent scale, in the circulating currents of the North Pacific.

In the space between Australia and New Zealand, the same operation is going on. To the westward is the southerly warm current just described. To the South this warm current is pressed upward by the northerly cold antarctic current. On the New Zealand coast this current is felt as far to the northward as Cook's Strait, while to the northward of the islands the warm equatorial and the cool polar currents by turns gain ascendency. This system developes one feature, that of a central space in which no current (except those dependent on the wind) is to be found. It is called by the whalemen the middle ground, and has been exceedingly productive to the New Zealand and Australian whale fishery. Its physical character we must suppose to be favourable to the production of the food of the whale, which perhaps flourishes here undisturbed by the transporting influence of currents unequalizing the temperature, and occasioning different water climates, so to speak, in the same locality. It is probable that the whales frequenting this middle ground came, or rather have come, to the shores of New Zealand, N.W. of Cook's Strait, to calve, in the bight called by the whalers Northerly Bay. However, it is most probable that the navigator, by availing himself of the various set of the currents, which will be elucidated by this theory, may greatly assist his passage across this part of the ocean.

We will cite some remarks that have been made on it.

Wilkes found, on approaching Lord Howe's Island and Ball's Pyramid from the Samoan Islands, a current setting North, in which direction his drift in the passage was 120 miles. In the neighbourhood of the first-named island the temperature fell to 66°, but on nearing the coast of Australia the warm southerly current raised it to 73°.-(Vol. v. p. 472.)

Capt. FitzRoy says:-On New Year's day, while in sight of the islets called Three Kings, we passed through several tide "races," one of which was rather "heavy," and would have been impassable for a boat. These races moved towards the North, while we could trace their progress. The temperature of the water fell 6° after passing through the principal one. Next day at noon we found that during the past twenty-four hours we had been set as many miles southward (S.S.E.), and hence I am inclined to infer that we were influenced by regular tide streams, rather than by currents setting always in one direction. To the succeeding day at noon (3rd) we were set only 7 miles by water, and that due East. Afterwards, in our passage to Port Jackson, we had alternately northerly and south-easterly currents of about 10 miles a day, and it was easy to tell which current we were in by the temperature of the sea while the stream set from the North, the water thermometer showed about 72°; but when the current was

running from the southward, the temperature of the ocean, a foot below as well as at the surface, was only 67°.*

D'Urville considered that Cook's Straits, the separation between the two larger islands, had been formed by the constant drift of the ocean to the S.E. (caused by the permanent N.W. winds) making a free passage through the group.

Though not immediately connected with the system just described, the following brief remarks may be given here respecting the currents around New Zealand. Wilkes considered that the antarctic drift strikes the southern part of the islands and forms currents on either side of the range, which, however, are not constant. That branch which flows on the western side appeared to be the strongest, and is felt as far to the North as Cook's Straits. The current which flows on the eastern side forms an eddy to the North of the islands.—(Vol. v. p. 473.)

Capt. Newby, sailing eastward from Cook's Straits in August, 1849, when on the meridian of the Chatham Islands, fell in with much tangle and sea-weed; this would indicate the northerly (polar) current before spoken of.

We shall now pass to the corresponding current to that flowing from the northward along the Australian coast, and becomes less in the cold polar current, to the corresponding stream in the northern hemisphere, which, it will be seen, is much more distinctly characterized, leaving all the minor features, or supposed distinct currents, to be adverted to hereafter.

7. THE JAPANESE CURRENT.

The movements of the waters, as well as of the atmosphere, seem to be on a more limited scale, and less decidedly marked, in the northern Pacific than they are in the southern hemisphere. This is probably owing to its comparatively enclosed character. From this cause it deserves, in some degree, the title of Pacific, and its navigation is not attended with any difficulty, as any ordinary ship may, with perseverance, work to windward in its central portion.

But towards its western side the movement of the ocean becomes manifest, and we find a great analogy in this respect to that of the North Atlantic, and accordingly, a very distinctly characterized current in the Pacific follows a parallel course to that of the Gulf Stream, well known in the Atlantic.

From the different configuration of the land, however, the absence of any western barrier, such as the Mexican coast presents to the western progress of the Atlantic waters, and the contraction of its channel by the Bahama Islands, this Pacific Gulf Stream has not such a distinct character as is seen in the Gulf of Florida. Still this warm ocean-river may be traced in its course by observation and analogy around the northern side of the North Pacific.

This current, in the earlier part of its course, has been noticed by several navigators, especially Capts. King, Krusenstern, and Broughton, whose remarks will be given presently.

The first point which may be noticed in it is the authority of the Japanese charts. On all of them, as shown by Siebold and Krusenstern, between Fatsisio

• Voyage of the Beagle, vol. ii. p. 620.

and the Mokiera Islands, that is, off the S.E. part of Nippon, South of Jedo, the capital, a current to the eastward is marked, called the Kuro Sirvo Stream, or as Krusenstern calls it, Kourosegawa, or the Current of the Black Gulf. The latter adds this remark :-"This current is 20 matsi (five-ninths of a Japanese ri, that is, about three-quarters of a mile) broad. For 10 matsi it has a very rapid course. In winter and spring it is very difficult to navigate, but in summer and autumn vessels can pass it." Of the exact velocity that this may be no account is given, but it is clear that it must be great, perhaps increased by passing through a contracted channel. It is important to notice it, and have such evidence in the early portion of its course.

Capt. Gore, after the deaths of Capts. Cook and Clerke, returned from the northward in the Resolution, making the coast of Japan in the beginning of November, 1779. Capt. King states, that, in this passage, when they approached the S.E. part of Japan, they were drifted by a strong current from the S. W., and that when they reached the latitude of 35° 43′, in eight hours, instead of making a course of 9 leagues to the S. W., they had been carried 8 leagues from the position they had left in a diametrically opposite direction, giving a velocity and direction to the current of at least four miles an hour to the N.E. by N., the longitude being 141° 16'. Capt. King makes the following comments on this:As the strong currents which set along the eastern coast of Japan may be of dangerous consequence to the navigator who is not aware of their extraordinary rapidity, I shall take leave of this island with a summary account of their form and direction, as observed at from the 1st to the 8th of November. On the 1st, at which time we were about 18 leagues to the eastward of White Point, the current set N.E. by N., at the rate of 3 miles an hour; on the 2nd, as we approached the shore, we found it continuing in the same direction, but increased in its rapidity to 5 miles an hour; as we left the shore it again became more moderate, and inclined to the eastward; on the 3rd, at the distance of 60 leagues, it set to the E.N.E., 3 miles an hour; on the 4th and 5th, it turned to the southward, and at 120 leagues from the land its direction was S.E., and its rate not more than 1 miles an hour; on the 6th and 7th it again shifted round to the N.E.; its force gradually diminishing till the 8th, when we could no longer perceive any at all."* This calculation would make it about 250 miles broad off this part of the Japanese coast.

The next authority we shall quote for it is Admiral Krusenstern, who, as is well known, passed to the eastward of the islands, September, 1804. From the introductory portion of his great work we extract the following:

The currents constantly run to the N.E. From the Strait of Sangar, as far as the parallel of 361°, we had daily a current, which carried us N.E. Į E., at the rate of 10 miles in the twenty-four hours. From the latitude of 36° to 351°, being about 70 leagues from land, it bore towards the E.N.E., with a velocity of 2 miles an hour. From the parallel of 35° to 34° the current bore to N.E.N., 1 miles an hour; we were then 60 leagues from land. Traversing the islands lying to the South of the Gulf of Jedo, we felt a current bearing to

* Cook's Last Voyage, vol. iii. pp. 404-5.

S.W., with a velocity of nearly a mile an hour; but after having passed these islands some degrees to the West, we again met with the former current bearing to the N.E.

When we discovered the coast of Japan upon the parallel of 31°, and particularly the southern part of the Isle Sikokf, the current carried us to the N.E., 3 miles an hour. Capt. Broughton ranged near the eastern coast of Japan during the months of November and July. We see by his journal that he constantly felt a current which carried him to the N.E., at 2 miles an hour, with this difference, nevertheless, that during the month of November the current bore more toward the North, and in July more to the East, but always between these two directions. We can conclude from the foregoing, that the currents upon the eastern coast of Japan are subjected to fixed laws, at least during the months of July, September, and October, and that their strength and force depend on the distance where they are met with from the coast. Capt. Colnett passed along the coast in March and April; it would be interesting to know what direction the currents then had, because a perfect knowledge of the currents in each season infinitely facilitates the navigation between Kamtschatka and Japan.

Thus far the definition of the Japanese current rests on positive evidence of unexceptionable character, as far as regards the seasons in which they were made. But its effects may be traced to the northward and westward.

It reaches the coast of Kamtschatka. Du Petit Thouars notices the mildness of the climate in the vicinity of Awatska Bay, and attributes it to the warm (Japanese) current coming from the south-westward, and thus ameliorates the severity of the winter. The comparative freedom from ice of the bays and inlets is also another evidence of its influence. The universal fogs which prevail, too, in the vicinity of the islands in the western portion of the Sea of Behring, arising, as is most probable, from the difference of temperature between the air and water, also indicates the same fact, and is perhaps analogous to the same phenomenon on the Banks of Newfoundland, arising from the Gulf Stream.

On page 603 (part i. of this work) the destruction of a Japanese junk is noticed. This occurred near the South end of the Kamtschatkan Peninsula in July, 1729. It was proceeding to the Port of Ohosaka in the South of Japan, and was drifted away by a violent storm to the N.E., and at last reached the place alluded to. This also is corroborated.

Another and similar circumstance is quoted on page 1124 (part ii.), of a Japanese junk which had drifted from its destination, and anchored, in December, 1832, at Oahu, Sandwich Islands. Although the currents in the vicinity of this group do not seem to be very well defined in their character, and we shall adduce one of an opposite nature, this circumstance must also be considered as an evidence of the easterly drift from Japan.

But we may look still farther to the East. A Japanese junk was wrecked near Cape Flattery, in Oregon, in 1833, as described on page 372 (part i.). This last is detailed by Washington Irving, in his "Astoria." These singular occurrences at once attest the tendency of the currents, and open a wide field for discussion on the migration of the inhabitants of eastern Asia and the peopling of the western world.

As an intermediate point where we may look for indirect evidence of the progress of this stream, the South extremity of Kodiack Island may be adduced. Here the remains of Japanese wrecks, recognised by the camphor-wood used in them, and other Japanese articles are found. We have no direct experiments recorded of the force or prevalence of the current to the South of the Aleutian Islands, but it may be supposed, from what has been said, to trend to the eastward towards the coast of N.W. America, and then assume a more southerly direction. This theory is confirmed by the ensuing remarks by Commander Wilkes, of the United States' Exploring Expedition :-Our passage from the Hawaiian group to the N.W. coast gave interesting results in relation to the currents. They were irregular until we reached the latitude of 27° N., after which we were strongly affected by a S.E. current, whose influence continued until we reached the coast of Oregon. At this time it ran at the rate of 50 miles in twenty-four hours; but when the Peacock traversed this same space, ninety days later, the velocity had not only diminished, but what current was found was nearly in an opposite direction. In relation to the extent of this S.E. current in the months of March and April, I have no precise information, nor can I supply it from others, since those who had previously visited this part of the ocean had not paid sufficient attention to this subject to furnish any precise data. All, however, agree in the fact, that they were affected by a S.E. current, often reaching the longitude of 130° W., and the latitude of 35° N.

We may conclude our remarks on this part of the ocean with the observations of Admiral Lütke, whose scientific character and ample means command all confidence:

In the same way that the constant West current within the limit of the N.E. trade-winds is explained by the constant easterly winds, so beyond this limit we met with such currents as the prevalent wind would afford an explanation. We met with but one exception to this rule. In the three traverses to the South of Kamtschatka and back again, between lat. 30° and 40° to 45°, and lon. 162° and 146°, we found, even with easterly winds, currents to the East. In our route from the Bonin-sima Islands to Kamtschatka, in May, 1828, we felt the first effect of this current, in lat. 33° 42′, where in two days it carried us 74 miles to the N.E., in calms and extremely light S.E. winds. From thence, in lat. 45°, we had for ten days, with only two exceptions, always currents to the East, although during all this time the wind was between S.E. and N. E., and that they blew sometimes very freshly. The mean action in this interval was 15 miles in twenty-four hours to N. 47° E. The current, after that, bore even more to S.E., but then during fresh winds from N.W. In the route from Kamtschatka to Ualan, in October and November, we found the first S.E. current in lat. 38° during S.E. winds; the currents towards the East quarter kept up for eight days, and the strongest occurred this time too in about lat. 34°, when we were drifted, in twenty-four hours, 35 miles N. 5° E., the wind nearly calm. Its mean action in these eight days was 8-6 miles in twenty-four hours, to the E.S.E. We found it in the same manner, and a year later, in lat. 40°, during a strong S.E. wind, or S.E. current. It was not then so marked, but as far as lat. 31° its general direction was towards the N.E. quarter, and afterwards, in lat. 2710, we again