NUTS of the anchor, two little prominencies, appearing like short square bars of iron, fixed across the upper-part of the anchor-shank, to secure the stock thereof in its place; for which purpose there is a corresponding notch, or channel, cut in the opposite parts of the stock, of the same dimensions with the nuts. See the article Anchor.
O.
OAKHAM, or OAKUM, the substance into which old ropes are reduced, when they are untwisted, loosened, and drawn asunder. It is principally used to drive into the seams, or intervals, between the planks of a ship, to prevent the water from entering. See the article Caulking.
White Oakum, is that which is formed of untarred ropes.
OAR, rame, (are, Sax.) a long piece of timber, flat at one end, and round or square at the other, and which being applied to the side of a floating-vessel, serves to make it advance upon the water.
That part of the oar which is out of the vessel, and which enters into the water, is called the blade, or wash, plat; and that which is within-board, is termed the loom, whose extremity, manche, being small enough to be grasped by the rowers, or persons managing the oars, is called the handle.
To push the boat or vessel forwards, by means of this instrument, the rowers turn their backs forward, and, dipping the blade of the oar in the water, pull the handle forward so that the blade at the same time may move aft in the water: But since the blade cannot be so moved, without striking the water, this impulsion is the same, as if the water were to strike the blade from the stern towards the head: the vessel is therefore necessarily moved according to this direction. Hence it follows, that she will advance with the greater rapidity, by as much as the oar strikes the water more forcibly. Thus it is evident, that an oar acts upon the side of a boat or vessel like a lever of the second class, whose fulcrum is the station, upon which the oar rests on the boat’s gunnel. In large vessels, this station is usually called the row-port; but in lighters and boats it is always termed the row-lock.
To ship the Oars, armer, is to fix them in the row-locks ready for rowing.
OBSERVATION, the art of measuring the altitude of the sun or a star, in order to determine the latitude, or the sun’s azimuth, &c.
OFF, an expression applied to the movement of a ship, when she sails out from the shore towards the distant sea. When a ship is beating to windward, so that by one board she approaches towards the shore, and by the other sails out to sea-ward, she is said to stand off and on shore, alternately. Hence,