that often prevails to the Westward cf Scilly. 185 
At ordinary times, its strength may not be great enough 
to preserve its line of direction, across the mouth of the Bri- 
tish Channel ; or, if it does preserve its direction, it may not 
have velocity enough to throw a ship so far out of her course, 
as to put her in danger. But, that a current prevails generally , 
there can be little doubt ; and its degree of strength will be 
regulated by the state of the winds. After a long interval of 
moderate westerly gales, it may be hardly perceptible ; for a 
very few miles of northing, in the 24 hours, will be referred 
to bad steerage, or some other kind of error : but after hard 
and continued gales from the western quarter, the current 
will be felt in a considerable degree of strength ; and not only 
in the parallel of Scilly, but in that of the south-west coast of 
Ireland likewise. 
Our observation of what passes in the most common 
waters, is sufficient to shew how easily a current may be in- 
duced, by the action of the wind, on the water contiguous to 
a bank, when the wind blows along it. In a canal of about 
four miles in length, the water was kept up four inches higher 
at one end, than at the other, by the mere action of the 
wind, along the canal. This was an experiment made, and 
reported to me, by my much lamented acquaintance, the late 
Mr. Smeaton. We know also, the effects of a strong south- 
west, or north-west, wind, on our own coasts : namely, that 
of raising very high tides in the British Channel, or in the 
Thames, and on the eastern coasts ; as those winds respec- 
tively blow : because the water that is accumulated, cannot 
escape quick enough, by the Strait of Dover, to allow of the 
level being preserved. Also, that the Baltic is kept up two 
feet at least, by a strong NW wind of any continuance : and 
