This is a one day marine chronometer signed Jn Heron, Greenock #124 on the dial and movement. Greenock is on the Clyde river in Scotland, and was a major ship building area. Jonathan Betts at the Greenwich Royal Observatory dates the chronometer to 1828. He states that it is the earliest known example of his work. Being a one day instrument, there is no wind indicator.

Here's Jerry's "Jn Heron" movement...