log

log¹

—loggish, adj.

/lawg, log/, n., v., logged, logging.

n.

1. a portion or length of the trunk or of a large limb of a felled tree.

2. something inert, heavy, or not sentient.

3. Naut. any of various devices for determining the speed of a ship, as a chip log or patent log.

4. any of various records, made in rough or finished form, concerning a trip made by a ship or aircraft and dealing with particulars of navigation, weather, engine performance, discipline, and other pertinent details; logbook.

5. Motion Pictures. an account describing or denoting each shot as it is taken, written down during production and referred to in editing the film.

6. a register of the operation of a machine.

7. Also called well log. a record kept during the drilling of a well, esp. of the geological formations penetrated.

8. Computers. any of various chronological records made concerning the use of a computer system, the changes made to data, etc.

9. Radio and Television. a written account of everything transmitted by a station or network.

10. Also called log of wood. Australian Slang. a lazy, dull-witted person; fool.

v.t.

11. to cut (trees) into logs: to log pine trees for fuel.

12. to cut down the trees or timber on (land): We logged the entire area in a week.

13. to enter in a log; compile; amass; keep a record of: to log a day's events.

14. to make (a certain speed), as a ship or airplane: We are logging 18 knots.

15. to travel for (a certain distance or a certain amount of time), according to the record of a log: We logged 30 miles the first day. He has logged 10,000 hours flying time.

v.i.

16. to cut down trees and get out logs from the forest for timber: to log for a living.

17. log in,

a. Also, log on, sign on. Computers. to enter identifying data, as a name or password, into a multiuser system, so as to be able to do work with the system.

b. to enter or include any item of information or data in a record, account, etc.

18. log off or out, Computers. to terminate a work session using a multiuser system, or a connection to such a system.

[1350-1400; ME logge, var. of lugge pole, limb of tree; cf. obs. logget pole; see LUGSAIL, LOGBOOK]

log²

/lawg, log/, n.

Math. logarithm.

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▪ nautical instrument

also called  maritime log 

      instrument for measuring the speed of a ship through water. The first practical log, developed about 1600, consisted of a pie-shaped log chip with a lead weight on its curved edge that caused it to float upright and resist towing. When the log was tossed overboard, it remained more or less stationary while an attached line (marked off with equally spaced knots) was let out behind the vessel for a measured interval of time (measured with a sandglass). The line and log were then hauled aboard and the speed of the ship determined by dividing the length of the line by the time interval.

      In the 19th century the log chip was replaced by a towed rotor or propeller connected by a line to automatic speed- and distance-measuring equipment. Two logs in use today are the pitometre log and the electronic log. The pitometre uses a pitot tube (see Henri Pitot (Pitot, Henri)) projecting through the bottom of the ship. The tube has one forward-facing and two side-facing orifices. When the ship is moving, pressure in the forward-facing tube exceeds the pressure in the side tubes; this differential is transmitted to equipment that translates it into a speed measurement. In the electronic log, which also protrudes through the bottom of the ship, a water-driven rotor turns a small electric generator, the current from which is proportional to the speed of the ship. This current is similarly used to produce a speed measurement.

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