622 PASSAGES OVER THE ATLANTIC. 



velocity of the current by the difference of latitude by account and ob- 

 servation. We say during the first day's work, because the generality of 

 common navigators make use of meridian altitudes of the sun alone to find 

 the latitude ; but it is very clear that altitudes of the planets and fixed 

 stars ought not to be neglected; not only because by this you cannot be in 

 doubt of your real latitude, but also, because they may be viore exact than 

 latitudes deduced from meridional altittLdes of the sun, lohen that luminary 

 passes in the proximity of the zenith, and because repeated observations 

 during the night assure, as much as possible, the situation of the ship. Thus 

 you may go on, with a clear idea of the operation of the current, and the 

 way that the ship is making. 



Having ascertained the velocity of the current, use can be made of it to 

 find the ship's departure, and this knowledge will be most important 

 when you fail in obtaining observations for latitude; because, in such a case, 

 wanting a knowledge of the difference of latitude given by the current, 

 you will be in want of everything ; but if you know the velocity of the 

 current, with it, and the course which it follows, you may find the 

 difference of latitude and departure which the current gives; and which, 

 though it will not give the position of the ship with that precision with 

 which it might be obtained by latitude observed, will still approximate 

 sufficiently to the truth to enable one to avoid danger, if prudence and 

 seamanlike conduct are combined. 



In addition to the directions previously given on pages 400 — 401, we 

 add the following, for the benefit of those who have had little experience in 

 the navigation, of sailing vessels especially, in these seas ; — 



1. — That it is most convenient to direct your course in mid-channel ; 

 not only because it is the farthest from danger, but because you will there 

 have the strongest current, which is desirable. 



2. — That, as you cannot ascertain, with all necessary certainty, the 



position of the ship, notwithstanding the rules given to diminish the errors 



occasioned by the currents, you ought, with the utmost care, to shun the 



Eastern coast of Florida, as being very dangerous, the Trade Wind 



blowing upon it ; while there is not the least risk in running along the 



Salt Kay Bank, and the edge of the Great Bank of Bahama. Upon the 



latter, also, you meet with good anchorages, very fit to lie in during the 



hard Northerly gales experienced between November and March, and 



which do not fail to cause many damages, and sometimes even force 



vessels to bear away, which is always dangerous, for the weather is 



always thick with such winds, and the worst case will be to run into one 



of them upon the coast of Cuba, when hoping to have made Havana or 



Matanzas. Hence, therefore, as soon as there is an appearance of a 



North, the best way is, if near the Salt Kay Bank, to anchor on it ; and, 



if near the Great Bank, to approach the edge of it, in order to be able to 



anchor when it may be necessary ; for although you may have a hard 



North, so long as you can lie-to in it, you ought to pursue your 



navigation, as the current will certainly carry the ship through the 



strait. 



3. — It is very necessary to sight the Kays on the Salt Kay Bank, even 

 though you have no fear of a^NortJi; and there may be occasions in which 



