EENNELL'S CUIUIENT. 303 



opposing coast, until a reverberation takes place, needs no demonstration. 

 The latter appears to be the case in the present instance. A long and 

 continual prevalence of Westerly and South-Westerly winds, in combina- 

 tion with a current that commonly sets into the Southern part of tho 

 Bay of Biscay, occasions an accumulation of water in the Bay, which seeks 

 an escape, by setting to the N.W. or W.N.W. 



It would be very difficult to understand that the great preponderance 

 of winds from the Westward of North and South, which prevail in the 

 latitudes off Cape Finisterre, should not have some effect in forcing the 

 water toward the coast ; and, if so, what can become of it, unless it forms 

 some Current, which we should very naturally expect to find would follow 

 the trend of the coast against which it is propelled. 



That such a Current does actually prevail is too well known to be doubted. 

 Mr. Kelly, the author of a treatise on Navigation, in two volumes, pub- 

 lished in 1733, gave a particular instance of it (Vol. i., page 434) ; by 

 which he shows that a ship becalmed with her sails furled for forty-eight 

 hours, was in that time carried by the current 46 miles to the Northward; 

 and we have many subsequent examples of vessels which have been set, 

 by the .course of the stream, to the Northward, or upon the rocks, of Scilly. 

 But the writer to whom we are more particularly indebted for an elucida- 

 tion of the subject, is the late Major Eennell,* who gave an illustration 

 of it, which placed it beyond all controversy ; and from whose paper, pub- 

 lished in the "Philosophical Transactions" of the year 1793, we extract 

 the following observations : — 



" In crossing the Eastern part of the Atlantic, the Rector, East India ship, 



* From the name of this gentleman, the Current is now generally denominated 

 Rennell's Cubrbnt. The Currents of the Ocean appear to have attracted the atten- 

 tion of Major Rennell at an early period, and they continued to occupy his attention 

 until the last ebb of his honourable life. The results appeared before the world in five 

 large charts, with a descriptive volume, dedicated to his Majesty King William the 

 Fourth, under the editorship of Mr. John Purd)', the original author of this volume. 



The Major's first Chart and Remarks on the Agulhas or South African Current 

 appeared in the year 1778, and the important pamphlet on the Scilly or 'thwart Channel 

 Current, in the year 1793. In the meantime, and subsequently, some cursory remarks 

 on the same subject were introduced in the " Illustration of the Geography of Herc- 

 dotus," the Philosophical Journals, &c. In or about the year 1810, on the suggestion of 

 a friend (Mr. Purdy), who expressed a wish to see all his writings on this subject com- 

 bined and republished, he commenced his Current Charts of the Atlantic Ocean, and col- 

 lected from the journals of his numerous friends a gleaning of information which, at 

 length, from repeated accumulations, presented a most beautiful and singular instance 

 of successful perseverance, on a subject never before attempted upon a plan so compre- 

 hensive. To an ordinary mind such a topic would have been regarded as dull, unin- 

 viting, and impracticable ; by the author it was appreciated according to its importance 

 and usefulness to mankind, and he treated it accordingly. He had long lamented the 

 general ignorance prevalent on this subject, and which had, from time to time, produced 

 so much loss of life and treasure, especially in relation to his native country. It is true 

 that, in later times, practice and experience had taught the mariner, in many cases, 

 how to shape his course to the best advantage ; but still he was deficient in theory, and 

 knew not the rationale, the why and wherefore, of the courses which he adopted, and the 

 variations which might be most advantageously made in his outward or homeward 

 passages, according to the fluctuations of season and circumstances. Such knowledge 

 is now, in a great measure, supplied. 



