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Soon theswift wing'd terrors fly;
doth nature's process heed,
Thou call'st each embryo member forth,
tove! and points to deity.
The seed of rice themselves have sown,
They eat! and for this madness groan.
Behold how curses, groans, and sorrow fails;
Happy the man whose healthy days,
presses on to all that's good;
Self is absorb'd in general love:
How bold his flight !
When Jesus shall the cong'ror prove;
To own that God is ONLY love,
Not land more welcome ; nor to traveller's ears
How beautiful the feet that go
God and king
purest flakes of purest snow
We have already briefly described the tides. We go on to observe that
the fluctuation of the tides produces another and more constant rotation of the waters of the ocean, from east to west, in this respect following the course of the moon. This may be considered as one great and general current of the waters of the sea; and although it be not every where perceptible, it is nevertheless every where existent, except when opposed by some particular current or eddy, produced by partial and local causes. This tendency of the sea towards the west is plainly perceivable in all the great straits of the ocean; as, for instance, in those of Magellan, where the tide, running in from the east, rises twenty feet high, and continues towing six hours; whereas the ebb continues but two hours, and the current is directed to the west. This proves that the flux is not equal to the reflux; and that from both results a motion of the sea westward, which is more powerful during the time of the flux than he reflux.
This motion westward has been sensibly observed by navigators in their passage hack from India to Madagascar, and so on to Africa. In the
great Pacific Ocean, also, it is very perceivable: but the places where it is most obvious are those straits which join one sea to another. In the Straits between the Maldivia Islands ; in the gulph of Mexico between Cuba, and Jucatan, In the straits of Paria, the motion is so violent, that it has received the name of the Dragon's Mouth. It is observed northward also, in the sea of Canada, in Waigat's straits, in the straits of Java, and in short, in every strait where the ocean on one part pours into the ocean on the other. In this manner therefore is the sea carried with an unceasing circulation round the globe ; and at the same time that its YOL. IV.
waters are pushed back and forward with the tide, they have thus 3 progressive current to the west, which though less observable, is not the less real.
But besides this general motion of the sea from east to west, there are many other currents which are confined to particular parts of it. These are found to run in all directions, east, west, north, and south; being formed by various causes; the proininence of the shores, the narrowness of the strai.s, the variations of the wind, and the inequalities of the bottom. These are of the greatest consequence to the mariner, and a knowledge of them is absolutely necesfury to their safety and success. It has often happened, that when a ship has unknownly got into one of these, every thing seems to go forward with success, the mariners suppose themselves every hour approaching their wished for port, the wind fills their sails, and the ship's prow seems to divide the waters; but at last, by sad experience, they find, that instead of going forward, they have been all the time receding. Currents, therefore, make a considerable article in the business of navigation; and the direction of their streams, and their rapidity have been carefully noticed. This has been done in different manners; as, by observation on the surface of the current; or by the driving of the froth along the shore; or by throwing out what is called the log-line, with a buoy made for that purpose, and by the direction and motion of this, they judge of the motion, and the rapidity of the current.
The setting of a current, or its progressive motion, may be either quite down to the bottom, or to a certain determinate depth. As the knowledge of their direction and velocity is of great importance 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 hitherto been practised by inariners 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 its ears or handles, so as to hang directly upright, as when placed upon the fire. This rope, which may be from seventy to an hundred fathoms in length, being prepared for the purpose, 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 of it are run out; after which it is fastened to the stern of the boat, by which she is restrained, and resides as at an anchor. The velocity of the current is then easily tried by the log and half-minute glass, the usual method of discovering a ship sailing at sea. The course of the stream is next determined by the compass provided for that operation. Having thus found the setting and drifting of the current, it remains to apply the whole to the purposes of navigation.
Currents are generally found to be most violent under the equator, where, indeed, all the motions of the ocean are most perceivable. Along the coast of Guinea, if a ship happens to overshoot the mouth of any river it is bound to, the current prevents its return; so that it is obliged to steer out to sea, and take a very large compass, in order to correct the