470 PASSAGES OVEB THE ATLANTIC. 



winter season ; every exertion should, therefore, be made to keep off this 

 dangerous and too often fatal coast. 



The depth of water, or quality of soundings in the North Channel, will 

 give little or no indication of the progress of the vessel, so that a good 

 look-out is here the mariner's best safeguard ; the coasts on both sides 

 being bold, excepting about South Eock and Maiden Eock, both of which 

 dangers are well lighted, but require a good berth in passing, particularly 

 the latter. 



In running through the North Channel with S. W. winds, every stitch of 

 canvas should be carried that the vessel will possibly bear, as these winds 

 often fly suddenly round to the N.W. quarter, see (122) and (128) ; and in 

 that case blow so hard, for twenty-four or thirty-six hours, as to compel a 

 vessel either to bear up for the South Channel, take a harbour, or lie-to in 

 a narrow and dangerous channel for a more favourable wind. 



(c) On pbooeeding by the South Channel, and thence Westward 



TO the Ocean. 



If it be intended to persevere in working down the South Channel, it will 

 be the best way to keep the Irish shore aboard by short tacks, should the 

 weather be squally with heavy rain, as the vessel will then have the benefit 

 of the N.W. wind and smoother water, should it fly round to that quarter, 

 as is often the case. In dry or moderate weather there is little fear of a 

 sudden shift of wind ; and a vessel, in such case, may make a long board 

 toward the coast of Wales. Should it come on to blow from the S.W., 

 with much rain, get the Irish coast on board as soon as possible, especially 

 in the winter. 



Vessels passing up or down the South Channel with Westerly winds 

 will find a strong indraught setting into Carnarvon and Cardigan Bays, as 

 well as into the Bristol Channel ; and this may be probably, in some degree, 

 accounted for by the following, and, perhaps, other causes : — Southerly, 

 S.W., and Westerly winds prevail over the Atlantic, between the Azores 

 and Great Britain, during eight or nine months of the year, causing the 

 surface-current in this vast space to flow to the Eastward ; the tides in 

 the neighbourhood of, and to some distance Westward of Scilly, run nine 

 hours out of the twelve to the Northward, or into St. George's Channel, 

 which, like the Strait of Gibraltar, has some resemblance in form to the 

 pipe of a funnel ; and it is probable that, in gales of wind from the S.W. 

 quarter, there is very little, if any, ebb from the Western edge of Channel 

 Soundings to a position 45 miles West from Scilly, and thence to the 

 Northward, on the same meridian, until within 45 miles of the South coast 

 of Ireland ; neither do I think it at all unlikely that a portion of the stream 

 of " Eennell's Current," which frequently, as I shall hereafter show, runs 

 with velocity to the N.W., may be diverted by Westerly gales into a more 

 Northerly direction, and being oppcytd in its course by the South coast of 

 Ireland, finds its way to the Eastward, and thus contributes to raise the 

 level of the water, and make a strong tiio or intiraughi into St. George's 

 Channel. 



