171 Remarks on the Marine Barometer, [April. 



consequences. A thorough knowledge of these consequences is 

 only to be acquired in the school of experience, and it is perhaps 

 for that reason that I feel anxious to impart the benefits of my own, 

 knowinoj that the warnings of this infallible monitor, have been but 

 too often fatally slighted. Because, forsooth, that part of the ocean 

 to whic h these remarks have reference, is frequently sailed over 

 without the occurrence of any thing approaching to a storm, and be- 

 cause the Barometer may, and does frequently remain nearly stati- 

 onary throughout the whole of this large portion of the voyage to 

 and from India ; is it therefore reasonable to infer that its utility 

 ceases ? on the contrary, the fact of the Barometer not being affect- 

 ed by any cliange in the atmosphere except when under the influ- 

 ence of an approaching storm, is the very circumstance which, in 

 my opinion, more particularly enhances its value. In high lati- 

 tudes, the eye of an experienced seaman will prove a tolerably correct 

 substitute for a Barometer, but the tropical hurricane, unlike the 

 storms of higher latitudes, but seldom gives any warning of its ap- 

 proach, and consequently the index of the Barometer affords the 

 only indication to be relied on. The practical inference which I 

 think myself at liberty to draw from these premises is, that when- 

 ever, or wherever within the tropics, or rather when in the more imme- 

 diate neighbourhood of the Equator, a rapid and considerable fall of 

 the quick-silver is observed to take place, it may be taken for granted 

 that an extraordinary degree of rarefaction of the surrounding air is in 

 progress, and that it will speedily be followed by a violent reaction. 

 From that moment the ship may be considered to have perforated 

 the confines of a circle, the centre of which will shortly become the 

 focus of a tornado, which, like the centre of a whirlpool in a differ- 

 ent element, cannot be approached but at the hazard of her destruc- 

 tion, a lot which may befal her in spite of any exertions, however 

 indefatigable, of the most skilful and able-bodied crew. I am aware, 

 however, that instances are to be adduced of ships having encoun- 

 tered hurricanes, without sustaining any serious injury, but I have 

 reason to believe that, in most of these instances, if not in all, it 

 would be found, were it possible to ascertain the fact, that the brunt 

 of the storm was in reality not encountered at all, that these ships 

 were throughout far nearer the verge of the circle of rarefaction than 

 its centre, that having been warned of its approach by the Barome- 

 ter, they had sufficient good sense and foresight not to neglect ite 

 But however this may be, no prudent man in command of a ship, 

 knowing as he must that the lives of all under his command depend 



