NavList:

The discussion of Railroad time has me wondering about Maritime time.  In the early 19th century, most major ports provided a time service, in the form of a 1 o'clock gun or time ball, for the use of mariners to set or check their timekeepers.

Did these local keepers of the time announce local time, requiring the mariners to make the necessary correction to Greenwich (or some other standard)?

And how were these local time signals determined?  Observation of the sun's meridian passage by set north-south reference marks, or by use of a high quality chronometer with occasional celestial checks?

Don Seltzer