122 LECTURES. 



Ovredo and in Herrera. And still nobody tried to lay down its 

 proper outlines on a map, which would have been the best way of 

 improving and correcting the knowledge of this important phenome- 

 non, so useful for navigators. We find on many maps, in the neigh- 

 borhood of Florida, legends like the following : " Here the water runs 

 continually to the north." How easy, at least so it seems to us, it would 

 have been instead of writing this down, to paint it by a few strips 

 of color ! And yet to make this step the inventive genius of a Frank- 

 lin was required ; for it was he who, towards the end of the eigh- 

 teenth century, was the first to depict the Gulf-stream and its limits 

 in a tolerable manner on a map, and thus give the first impulse to 

 the improvement of our current-maps, which now form so important 

 a branch of the art. This general omission of the currents on the 

 maps is all the more strange inasmuch as geographers were long ago 

 accustomed to make an exception with regard to one particular cur- 

 rent. The famous maelstrom, on the coast of Norway, can be seen 

 on very old maps. We find it there regularly indicated with a long, 

 rough, spiral line. It did not strike the artists that what they did 

 here could, with great propriety, have been extended further. 



The regular trade winds between India and Arabia, with their na- 

 ture, direction, and changes, were not only known but daily taken 

 advantage of by navigators for centuries. So, too, the trade winds of 

 the Atlantic were described, discussed, and used, at least since the 

 time of Columbus. Nevertheless, though these air currents flow with 

 nearly the same regularity as rivers, no map-maker gave any visible 

 hint respecting them to the navigators to whom he pretended to fur- 

 nish useful charts, until the time of our modern Eennells. Wind-maps 

 are also a very late invention of our centui-y. 



That the level surface of the ocean covered very difierent depths 

 of water was ascertained in the earliest stages of navigation, the 

 sounding line being an instrument the necessity of which was soon 

 recognised. The able Spanish navigator Alaminos, for instance, not 

 to speak of many earlier ones, had explored tolerably well not only the 

 currents and directions of the winds in the Mexican Gulf, but also 

 that remarkable bank which runs along the west coast of Florida, 

 and is known under the name of "The Tortugas Soundings." And 

 yet it was not till more than two centuries after Alaminos that the 

 Spanish hydrographers began to depict that important feature of the 

 Mexican Gulf by running a dotted line round its limits. 



The existence of the Banks of Newfoundland was known to the very 

 first discoverers of the eastern coast of North America. Nay, for a 

 long time these banks were the most frequented part of the North Ameri- 

 can waters, being visited, since the year 1504, by whole fleets of French, 

 Portuguese, Spanish, and English fishermen. To have a true conception 

 of their configuration, extent, varying depths, currents, and other cir- 

 cumstances, was almost of greater importance for all the navigating 

 nations of Europe than to know the configuration of the coasts of the 

 great continent itself. Yet, at a time when the whole east coast of North 

 America was already very well represented on the maps, we see the 

 George's bank, Nantucket shoals, and the other great banks before this 



