"For sale by the Hydrographic Office, Washington, D.C., also by the Superintendent of Documents Government Printing Office, Washington, D.C. Price 90 cents." Further tables on paste-downs and p.

(1) NAUTICAL astronomy is simply the application of spherical trigonometry to the problem of ascertaining the latitude and longitude at sea by observations of the heavenly bodies; as also the errors ...

SINCE the very general adoption of the method of navigation known as the Marcq system of position lines, in which, whatever the azimuth, the position line is determined by one and the same problem, ...