in the Jewish antiquities, a measure which contained a quarter of a cab, and consequently five sixths of a pint. There is mention made of a log (2 Kings, vi. 25) under the name of a fourth part of a cab. But in Leviticus the word log often signifies the measure of oil which lepers were to offer at the temple after they were cured of their disease. Dr Arbuthnot thinks that the log was a measure of liquids, the seventy-second part of the bath or ephah, and the twelfth part of the hin.

nautical term, signifying a small piece of timber, of a triangular, sectoral, or quadrantial figure, generally about a quarter of an inch thick, and five or six inches from the angular point to the circumference. It is balanced by a thin plate of lead, nailed to the arch, or circular side, so as to swim perpendicularly in the water.

Log-Line, a little cord or line, fastened to the log by means of two legs, one of which passes through a hole at the corner, and is knotted on the opposite side, whilst the other leg is attached to the arch by a pin fixed into another hole, so as to draw out occasionally. By these legs the log is suspended in equilibrium; and the line thus annexed to it is wound round a reel, fixed for that purpose in the gallery of the ship.

The use of the log and log-line is to keep account and make an estimate of the ship's way or distance run, which is done by observing the length of line unwound in half a minute's time, told by a half-minute glass; for so many knots as run out in that time, so many miles the ship sails in an hour. Thus, if there be four knots veered out in half a minute, the ship is computed to run four miles an hour. The author of this device for measuring the ship's way is not known; and no mention of it occurs till the year 1607, in an East India voyage published by Purchas; but from that time its name occurs in other voyages amongst his collections, and henceforward it was noticed both by our own authors and by foreigners; as by Gunter in 1623, Snellius in 1624, and by almost all the succeeding writers on navigation.

The log is a very precarious mode of computation, and must always be corrected by experience, much uncertainty arising from the motions of the ship, the winds of variable force, the friction of the reel, and the lightness of the log in the course of the current. See Navigation.

Perpetual Log, a machine so called by its inventor, Mr Gottlieb of London, is intended for keeping a constant and regular account of the rate of a ship's velocity in the interval of heaving the log.

Log-Board, a sort of table, divided into several columns, containing the hours of the day and night, the direction of the winds, the course of the ship, and all the material occurrences that happen during the twenty-four hours, or from noon to noon; together with the latitude by observation. From this table the officers of the ship are furnished with materials for compiling their journals.

Log-Book, a book into which the contents of the log-board are daily copied at noon, together with every circumstance deserving notice which happens to the ship, either at sea or in harbour.