On the contrary, if we find the ship a-head of the reckoning on one day, and a-stern of it on another, we have reason to believe that such errors are owing to accidental causes, and not to currents.  This seems to have been the case in our passage between England and Teneriffe.  But, from the time of our leaving that island, till the 15th of August, being then in the latitude of 12 deg.  N. and longitude 24 deg.  W. the ship was carried 1 deg. 20’ of longitude to the westward of her reckoning.  At this station the currents took a contrary direction, and set to E.S.E. at the rate of twelve or fourteen miles a day, or twenty-four hours, till we arrived into the latitude of 5 deg.  N. and longitude of 20 deg.  W.; which was our most easterly situation after leaving the Cape de Verde Islands till we got to the southward.  For in this situation the wind came southerly, and we tacked and stretched to the westward; and, for two or three days, could not find that our reckoning was affected by any current.  So that I judged we were between the current that generally, if not constantly, sets to the east upon the coast of Guinea, and that which sets to the west toward the coast of Brazil.  This westerly current was not considerable till we got into 2 deg.  N. and 25 deg.  W. From this station to 3 deg.  S. and 30 deg.  W. the ship, in the space of four days, was carried 115 miles in the direction of S.W. by W. beyond her reckoning; an error by far too great to have any other cause but a strong current running in the same direction.  Nor did its strength abate here; but its course was afterward more westerly, and to the N. of W., and off Cape Augustine N. as I have already mentioned.  But this northerly current did not exist at twenty or thirty leagues to the southward of that Cape, nor any other, that I could perceive, in the remaining part of the passage.  The little difference we afterward found between the reckoning and observations, might very well happen without the assistance of currents, as will appear by the table of Day’s Works.[90]

[Footnote 90:  The curious reader will find some interesting, though not decisive, remarks concerning the currents of the Atlantic Ocean in Clerke’s Prog. of Mar.  Disc. vol. i. p. 358.—­E.]

In the accounts of my last voyage, I remarked, that the currents one meets with in his passage generally balance each other.  It happened so then, because we crossed the Line about 20 deg. more to the eastward than we did now; so that we were, of consequence, longer under the influence of the easterly current, which made up for the westerly one.  And this, I apprehend, will generally be the case, if you cross the Line 10 deg. or 15 deg. to the E. of the meridian of St Jago.