on which this last theory is founded are not so conclusive as those of the former.

This united current flows from West to East along the whole extent of the Pacific, gathering in volume as it approaches the western coast of America. But in about 160° W. long. it separates into two branches. The northern branch, continuing to flow E.N.E. and East as far as the meridian of 80° W., then suddenly turning round North, N.W., and W.N.W., has received the name of the Mentor Current, and mingles with the southern part of the equatorial current, flowing West.

The other branch of this eastern current, formed mostly by the waters of a lower temperature, flows in part to the northward along the West coast of America, where it forms the cold current of the coast of Peru, called also Humboldt's Current; the other part sets to the southward along the southern coast of South America, where it forms the cold current of Cape Horn, taking its course round this cape into the Atlantic Ocean.

The foregoing is considered the southern counter-current of the Pacific ocean. The observations, however, on which it is assumed are not yet sufficient to establish that it does so beyond question, but only seem to indicate it as most probable.

The southern limit of this current, according to the same theory, will be difficult to establish, from the tendency of the cold water to flow towards the equator. But from the combined tendency of the waters to flow from the southward towards the equator with those flowing from West to East, a mean variable direction results, according to the relative strength of these currents.

There is little information concerning the temperature of this counter-current, but it appears that on the parallel of 60° S. lat. the mean temperature was found to be 33°; in 50° lat., 36°; in 45° lat., 43°; in 35° lat., 65°.

The rate of this current at its commencement, between Tasmania and Campbell Island, was found by Freycinet to be on an average 40 miles a day easterly; 29 miles between Campbell Island and the meridian of 140° W. long., its direction being N.E. and N.N.E.; and 17 miles between the meridians of 140° and 100° W. long., its direction being N.E. The rate of this current must be very variable and greatly influenced by winds from N.W. to West and S.W. which blow constantly in this zone of the Pacific Ocean, and often with considerable strength.

Northern Branch of the Counter-Current.—The northern branch of the abovementioned Mentor Current loses itself in the equatorial current. It always flows eastward as far as the meridian of 80° W., when it turns round suddenly by the North to West.

The breadth of this current varies from 350 to 800 miles. Its eastern limit closely approaches Humboldt Current.

Near the parallel of 26° S., where it runs N.E., N., and N.W., in the month of May its rate was found to vary from 18 to 21 miles a

day. In its southern part, at the same season, it varied from 10 to 22 miles.

The following temperatures were found in the Mentor Current, crossing it from West to East: at its western limit 72°; 69° in its middle; and 67° at its eastern limit, on the parallel of 33° S. lat. In May the temperature was found to be 67° at this same eastern limit of the current, in 26° S. lat.

The attention of mariners should be directed to this current. The islands of Felix and Ambrose will be found nearly in the midst of it. Southern Branch of the Counter-Current.—The second or southern branch of the counter-current, after flowing eastward, becomes divided, forming two considerable currents, one setting S.E. and South, the other N.E. and North. This division takes place nearly on the parallel of 46° S., and about the meridian of 81° W.

The S.E. branch forms the current of Cape Horn, alluded to in considering the currents of the Atlantic Ocean. The northern part, flowing N.E., forms the cold current of the coast of Chili and Peru, and has received the name of Humboldt Current.

Current of Cape Horn.-The current of Cape Horn is first found at about sixty leagues from the coast of America, where its principal direction is E.S.E. and S.E. It then becomes S.S.E., and near the coast it assumes the same direction, flowing towards Cape Horn and preserving a breadth of about sixty leagues. Near the land it follows the windings of the shore, but at its outer limit it becomes gradually more easterly as it advances southward towards the South extremity of the land. It thus follows its easterly course round Cape Horn, extending on the meridian of this cape to the southward as far as about the parallel of 60° S. lat. Having passed the meridian of Cape Horn, it takes an E.N.E. direction and flows N.E. into the Atlantic Ocean.

The velocity of this current of Cape Horn varies from ten to twenty miles a day, but it increases as it advances southward near Terra del Fuego, varying from twelve to twenty-five miles a day to the westward of it. Westerly winds accelerate it in proportion to their force, and it becomes imperceptible with S.E. winds. To the eastward of Terra del Fuego, and a little North of Staten Land, the rate of this current was thirty-three miles per day.

On the parallel of Chiloe Island the temperature of the current of Cape Horn in April was 58°; on the parallel of the entrance of Magellan Strait 49°; a little East of the meridian of Cape Horn, 44°; and near Staten Island, 42°.

Humboldt Current.-The current of cold water which flows northward along the coast of Chili and Peru, called Humboldt Current, mingles at first with the Cape Horn Current, separating from it on the parallel of 43° S., flowing E.N.E. and N.E. on the parallel of Valdivia. Off Valparaiso its principal direction becomes N.N.E. and North, and it continues flowing along the coast of America as far as the parallel of Arica. Beyond the bend in the coast where Arica is situated the general direction of the coast of Peru is N. 50° W. as NO. 5.-VOL. XXVIII. 2 P

far as Cape Blanco, in 5° S. Humboldt Current, after making the tour of the bend in which Arica is situated, continues to follow the direction of the coast to the N.W., and on gaining the parallel of Payta, near Cape Blanco, it leaves the coast, turning suddenly W.N.W., passing the Galapagos Islands, its North limit being nearly thirty leagues North of them. It thus enters the northern hemisphere of the Pacific Ocean, reaching as far as 2° N., increasing gradually as it flows West and losing itself in the Equatorial Current.

The extent of this current from the coast varies considerably. On the parallel of Valparaiso it is 120 miles; it increases as it flows northward and when, off Payta, it leaves the land, flowing W.N.W., its distance from the coast is nearly 180 miles. On the meridian of the Galapagos its extent is about 500 miles, and it is also the same on the meridian of 105° W.

Occasionally, however, anomalies are found in this current. Thus, in some places, instead of North it flows South at the rate of half a mile or a mile, and even more.

The times at which these changes take place cannot however be anticipated. There seems no apparent cause to occasion this southerly set, which is often met with immediately before or after northerly winds. But this is not always the case, and must not be considered as a general rule.

In the immediate vicinity of the coast of Chili and Peru in many parts a counter-current to that of Humboldt, flowing principally to the southward, is found, following the windings of the shore, with a velocity varying from three to twelve miles a day. This counter-current is necessarily produced by the Humboldt Current.

The temperature of the water of the Humboldt Current increases gradually as it flows to the northward; but the increase is considerable, as may be seen by the following observations:-In the latitude of Valparaiso the temperature of the current has been found to be 53°; on the parallel of Coquimbo it was 57°; on that of Cobija, 64°; on that of Arica, 65°; off Pisco it was 66°; on the parallel of Lima, 66°; on that of Truxillo, 69°; and on that of the cape of Blanco, 74°, the eastern limit of the current; and 66° on the western limit.

On leaving the current a little North of Cape Blanco, after a few hours the temperature of the sea was found to be 9° more than the temperature of the current.

The rate of the Humboldt Current is very variable, as it meets with other currents. In general its rate is greater near the coast than out at sea, as is the case with all those that flow along the coasts of continents, a circumstance observed by Humboldt. The minimum rate of it, by the Bonite, from Valparaiso to Payta, was three miles; the maximum is twenty-six miles a day. The first was found between Cobija and Callao; the other between Callao and Payta. The Venus, from Valparaiso to Payta and the Galapagos, found the minimum rate to be six miles, the maximum twenty-six miles a day: the first on the parallel of Arica; the last between Valparaiso and

Cobija. Humboldt concludes from these observations from Valparaiso to Coquimbo, and principally from Arica to Lima, that the rate of this current is from twelve to fourteen, and even eighteen miles a day.

When the Humboldt current runs N. W., suddenly leaving the coast, in the latitude of Cape Blanco, its general rate is about eight miles a day, and the mean rate of it, from these observations, was about fifteen miles a day.

The importance of this current to navigation may be easily understood for vessels from South to North. They make the run from Valparaiso to Callao in nine or ten days, and from Callao to Guayaquil in four or five days. On the contrary, it requires weeks and even months to make the return voyages, especially if the coast is kept, when the route is often impracticable.

Equatorial Current of the Pacific.-The southern limit of the Equatorial Current is considered nearly on the parallel of 26° S.; its northern limit, with some modification, is on the parallel of 24° N. Thus the waters of the Pacific Ocean, in a zone comprising 50° of latitude (nearly one-third of the distance between the poles), have a regular motion towards the West. However, within the limits of this zone and a little North of the equator, a stream of water flowing from West to East, which would appear to separate the whole Equatorial Current into two,-one North and the other South. This countercurrent, which is in a great measure caused by the Equatorial Currents themselves, traverses the whole of the Pacific Ocean from West to East.

The rate of the Equatorial Current varies considerably. It has been found setting from thirty to fifty and nearly sixty miles a day. Its mean rate is from twenty-four to twenty-five miles a day. In considering this current generally it will be better to take it in its two divisions, as it is separated by the equatorial eastern stream abovementioned, and we shall first refer to the Equatorial Current of the Southern hemisphere.

South Equatorial Current.-The South Equatorial Current is first experienced on the meridian of 90° W. Its southern limit is just to the northward of the southern tropic of Capricorn, and South of Pitcairn Island; thence it flows westward, nearly along the parallel of 26° S., as far as the meridian of the Tonga Islands.

Near this archipelago the current becomes separated into several branches; one of which has received the name of Rossel: its influence is felt on the South coast of New Guinea and in Torres Strait. The current is tolerably steady among the several groups of islands in this part of the Pacific Ocean, even during the N.W. monsoon.

Another branch of the South Equatorial Current runs along the eastern coast of Australia and as far as Tasmania, forming the warm Australian current, known as the counter-current of the South Pacific Ocean.

Between the parallels of 20° and 10° S. it is found that the mean temperature of the South Equatorial Current varied from 76° to 78° between the meridians of 107° and 122° W.; it has been observed to

be 79° to 81° between the meridians of 122° and 137°. Near Tahiti it has been found to be 82°. On the meridian of 188° and the parallel of 8° S., it has been found to be 84°, which is its maximum in the southern hemisphere.

The temperature of the sea out of the current has been estimated at 67°, that is from 9° to 18° below that of the Equatorial Current of this hemisphere.

Rossel Current.-The Rossel Current is a continuation of the South Equatorial Current, and was first noticed by Admiral Rossel in the voyage of D'Entrecasteaux. It receives the name when West of the Tonga Islands, or about North of the island of Tongataboo. Its northern limit is South of the archipelago of the Fejee Islands. It runs to the N.W. and the N.N.W., at about fifty or sixty leagues East from the archipelago of the New Hebrides. It then passes to the northward of the island of Vanikoro and South of Santa Cruz, where it continues flowing West, and is lost South of the island of San Christoval, one of the islands to the S.E. of the Solomon Islands. The southern limit of this current, the volume of which increases in proportion as it is further West, is to be found nearly on the parallel of 25° S. It then flows W.N.W., passing southward of New Caledonia, where another branch of the Equatorial Current turns to the S.E., joining the warm current of Australia, flowing along the eastern coast of this continent.

The chief direction of the Rossel Current is W.N.W. and N.W. Its temperature is 78°. It is found as far as Torres Strait, and has an average rate of from eight to ten miles a day. Its maximum is about eighteen and its minimum four miles.

Current of the East Coast of Australia.-Along the East coast of Australia there is a general current and a periodical current.

The general current of this coast-a branch of the Equatorial, or rather a continuation of it-only takes that name on the parallel of Sandy Cape and on the meridian of 167° E. Its direction is S.W. as far as about 30° S., and it continues along this parallel to 480 miles from the coast. South of the parallel of 30° S. its direction is nearer S.S.W., and it becomes more southerly in proportion as it approaches Tasmania.

Its extent from the coast is about 300 miles on the parallel of 30° as far as the southern extreme of Tasmania, where it divides into two branches. The least, which flows round Tasmania, returns along the West coast of that island to the N.N.W. The other, flowing S.E., meets the cold waters flowing to the northward from the southern latitudes, and, taking an easterly direction, forms a part of the counter-current of the Pacific already mentioned.

The temperature of the Australian Current on the parallel of Port Jackson is 64° at its easten limit; 70° in the middle; and 68° near the coast.

This temperature rapidly decreases to the southward. For instance, on the parallel of Bass Strait it is 60° at its East limit, and the direction here is S. W. South of Tasmania the temperature was found to