354 Captain HalPs Notice of a Voyage of Research. 



compass it is still worse : Yet it is obviously of the greatest 

 importance, when steering for any port, especially at night, to 

 know what reliance is to be placed on so fickle a guide as 

 the compass — a guide, it may be remarked, whose tendency at 

 every moment is to deceive — who never tells the same story twice 

 — and who is drawn out of his path by a thousand attractions, 

 which, if not duly watched and counteracted, render his ser- 

 vices, like those of a drowsy pilot, the very means of our destruc- 

 tion. 



This subject has only very recently been attended to in this 

 hemisphere, scarcely at all in the other. It is, however, a ques- 

 tion of such vital importance to navigation, that the experiments 

 suggested by Professor Barlow, and since so ably followed up by 

 Captain Parry and Lieutenant Foster during the recent expe- 

 dition, should be carefully repeated in the south, and the prac- 

 tical efficacy of the correcting plate invented by the eminent 

 philosopher alluded to, practically examined in remote places, 

 and under various circumstances. We shall thus learn the full 

 extent of this beautiful discovery, which removes the most dis- 

 tracting source of erroneous reckoning that has ever annoyed 

 the navigator. 



The phenomena of the winds, though less readily made the 

 subject of observation than the points already alluded to, ought 

 to be investigated in a manner they have never yet been. At 

 first sight, the winds appear less under the influence of known 

 laws than any other element with which the navigator has to 

 concern himself. But experience seems to show, that it is 

 otherwise, since a practised sailor, in a dull sailing ship, will ge- 

 nerally make a better passage than one who is not experienced, 

 though in a faster sailing vessel. In almost every part of the 

 globe, the prevalent winds are found to be more or less under 

 the influence of laws capable of being distinctly stated, but 

 which have not as yet been recorded in such a manner as to 

 be intelhgible, and practically useful to the seaman. On the 

 other hand, it has happened that theoretical men, by not taking 

 into account local causes, of which, from want of actual ex- 

 perience, or any correct accounts, they could have no just 

 knowledge, have rather contributed to embarrass than to re- 

 lieve the navigator. Even the well-beaten track, where the 

 trade- winds prevail, is imperfectly and often erroneously de- 



