| Description | Description of an artificial horizon designed by Leigh to be attached to a Davis's quadrant (John Davis (c.1550–1605)). An addition to aid in navigation at sea when visibility is poor. Includes a figure of the water level in coloured ink.
Subject: Navigation / Scientific apparatus and instruments
Read to the Royal Society on 3 November 1737
Published in Philosophical Transactions as ' A description of a water-level to be fix'd to Davis's quadrant, whereby an observation may be taken at sea, in thick and hazy weather, without seeing the horizon' |