A new sett of logarithmic solar tables, calculated and constructed for determining the latitude at sea, by Taking two Altitudes either in the Forenoon or Afternoon, with the intermediate Time by a common Watch; and that with Ease and Accuracy, independent of the Sun's Meridional Altitude. This Most Excellent and Useful Performance, does not only produce the true Latitude at any Time between Nine O'Clock in the Morning, and Three in the Afternoon; but also gives the true Time of the Day, when the greatest Altitude was taken to thirty Seconds by the Tables; and if a greater Degree of Accuracy is required, the same may be done by taking Proportional Parts. Whence the Sun's true Azimuth may be determined by One single Proportion.

Date:

1759