The Ship's Logs

USS CONSTITUTION Log for 20 August 1812

A ship's log is the official record of the activities of a ship and the men who make up her crew. 
Included are courses steered and speed made good, port departures and arrivals, stores taken
aboard or jettisoned, battles fought, other ships met, the arrivals and departures of people, the
weather experienced, groundings, collisions, and anything else thought noteworthy. 

Until the 1840s, a "day" in the log ran from noon to noon when the ship was at sea to conform with
the fact that correct time was maintained by determining the precise instant of local apparent noon
through noting the sun's high point in the sky. 

Then, when chronometers -- very accurate timepieces -- became common in men-of-war, log-keeping
 was changed to conform to "civil" practice, i. e., midnight-to-midnight. 

In the files that follow, all the early entries have been adjusted to reflect the later practice (midnight-to-midnight).