CURRENT (continued)

" On the shore of China and Cambodia, in the months of October, November, and December, the currents set to the N. W. and from January to the S. W. when they run with such a rapidity of motion about the shoals of Parcel, that it Seems swifter than that of an arrow.

" At Palo Condore, upon the coast of Cambodia, though the monsoons are shifting, yet the currents set strongly towards the east, even when they blow to a contrary point.

" Along the coasts of the bay of Bengal, as far as the cape Romania, at the extreme point of Malacca, the current runs southward in November and December.

" When the monsoons blow from China to Malacca, the sea runs swiftly from Pulo Cambi to Pulo Condore, on the coast of Cambodia.

" In the bay of Sans Bras, not far from the Cape of Good Hope, there is a current particularly remarkable, where the sea runs from east to west to the landward; and this more vehemently as it becomes opposed by the winds from a contrary direction. The cause is undoubtedly owing to some adjacent shore, which is higher than this." Varenius.

These currents constantly follow the winds, and set to the same point with the monsoon, or trade-wind, at sea. See MONSOON.

In the streights of Gibraltar the currents almost constantly drive to the eastward, and carry ships into the Mediterranean: they are also found to drive the same way into St. George's channel.

The setting, or progressive motion of the current, may be either quite down to the bottom, or to a certain determinate depth.

As the knowledge of the direction and velocity of currents is a very material article in navigation, it is highly necessary to discover both, in order to ascertain the ship's situation and course with as much accuracy as possible. The most successful method which has been hitherto attempted by mariners for this purpose, is as follows. A common iron pot, which may contain four or five gallons, is suspended by a small rope fastened to it's ears or handles, so as to hang directly upright, as when placed upon the fire. This rope, which may be from 70 to 100 fathoms in length, being prepared for the experiment, is coiled in the boat, which is hoisted out of the ship at a proper opportunity, when there is little or no wind to ruffle the surface of the sea. The pot being then thrown overboard into the water, and immediately sinking, the line is slackened till about seventy or eighty fathoms run out, after which the line is fastened to the boat's stem, by which the is accordingly restrained, and rides as at anchor. The velocity of the current is then easily tried by the log and half-minute glass, the usual method of discovering the rate of a ship's sailing at sea. The course of the stream is next obtained by means of the compass provided for this operation.

Having thus found the setting and drift of the current, it remains to apply this experiment to the purposes of navigation. If the ship sails along the direction of the current, then the motion of the ship is increased by as much as is the drift or velocity of the current.

Reference Works