“ As a very slight error in the position of a light or buoy, dot, cross or figure, might lead to grave disaster, every symbol on the admiralty chart has been delineated with great care and consideration, and no pains are spared in the effort to lay before the public the labours of the nautical surveyors and explorers not only of England, but of the maritime world; reducing their various styles into a comprehensive system furnishing the intelligent seaman with an intelligible guide, which common industry will soon enable him to appreciate and take full advantage of. ”

“ These are known as the soundings, indicating in fathoms or in feet (as shown upon the title of the chart) , at low water of ordinary spring tides, the least depth of water through which the ship may be sailing. ”

“ In addition to the work of British sailors, the labours of other nations have been collected and utilized. Charts of the coasts of Europe have naturally been taken from the surveys made by the various nations, and in charts of other quarters of the world considerable assistance has been received from the labours of French, Spanish, Dutch and American surveyors. Important work is done by the Hydrographic Office of the American navy, and the U.S. Coast and Geodetic Survey. The admiralty charts are published with the view of meeting the wants of the sailor in all parts of the world. ”