This is a very ingenious contrivance, which measures time well in both rough weather and fine.

It is simply a bucket half filled with water, in which floats the half of a well-scraped cocoa-nut shell.

In the bottom of this shell is a very small hole, so that when placed to float in the bucket a fine thread of water squirts up into it.

This gradually fills the shell, and the size of the hole is so adjusted to the capacity of the vessel that, exactly at the end of an hour, plump it goes to the bottom.

The watch then cries out the number of hours from sunrise and sets the shell afloat again empty.