Page:Journal of the Asiatic Society of Bengal Vol 1.djvu/372

330 used of course with much more elaborate care than for the common purposes of the practical voyager.

Seeing, therefore, how entirely dependent geography has been, and still is, and, for a long time to come, must be upon navigation, we learn to appreciate the labours of those marine surveyors and careful scientific navigators, through whom we have arrived at a correct knowledge of the positions of islands, and of the figure of continents, and of the bays and rivers, and rocks and sand-banks, which distinguish the shores of seas and oceans, and thus are enabled to compile a chart which shall accurately exhibit the phænomena of the earth's surface, and enable future voyagers to steer boldly to ports they have never before visited; astonishing the native inhabitants by the display of more information on the subject than they possess themselves.

There is nothing however more deceitful, or that ought to be received with more distrust than a chart or nautical survey, with the author of which and the materials of construction we are unacquainted. There is not a midshipman nor a captain's clerk in the mercantile navy that cannot take a latitude and a bearing, and with the help of the printed navigation tables, make an approximate calculation of the longitude. Nobody, therefore, that sails in a ship which happens to light upon strange lands, or upon objects of any kind not laid down in previous charts, fails to assign at once a locality to what he sees; and if the time allows him to cast anchor, a chart is constructed from a series of bearings, and produced with as much confidence as if made from the best trigonometrical data. If the author of the discovery be a man of credit and intelligence, his chart is incorporated in those published to the world, and continues, with all its defects, to be given out as the best record possessed of the portion of the earth's surface delineated. This is exactly as it should be, and no one in his senses, would wish such information and materials to be suppressed; but the difference is wide between the sketch of a casual voyager of this kind, put together from compass bearings, and logboard distances, and computed latitudes and longitudes, and the accurate delineation of the practised nautical surveyor employed to verify, and to ascertain once for all, the exact position and outline of what has been hitherto vaguely and imperfectly known and reported.

The Governments of British India are entitled to much credit, for the manner in which the means at their disposal have been employed in furthering the advance of our geographical knowledge, by surveys of this kind. The department has, in the seas to the eastward of the Indian peninsulas, been for many years under the direction and personal management of Captain Ross, Senior Commander in the Indian Navy, and Marine