NOTES ON BRAZIL. 



13 



which the navigator should carefully observe, depend upon the winds 

 which have blown between either tropic and the line. 



They are not so steady as has been sometimes represented, and seem 

 to be very materially affected by the relative positions of the Sun and 

 Moon. It is evident that both these luminaries produce a tide in the 

 atmosphere ; and sometimes counteract each other's influence. This 

 occurs in the smallest degree when the new and full moons happen with 

 the least difference in the declinations of the two bodies. In propor- 

 tion as this increases, their operations on the air become disturbed, and 

 every month, a vessel within the tropics must be placed, unavoidably, 

 between the foci or points upon which their influence most immediately 

 falls. In such a situation she will probably meet with calms. The winds 

 will freshen continually in proportion as the moon approaches and passes 

 over her, or recedes and leaves the influence of the sun more predominant. 

 Hence it seems, that the irregularities of the Trade Winds, so frequently 

 noticed, and especially of the south-eastern Trades, may be connected 

 with the Cycle of the Moon, and return periodically. An attentive 

 Officer observes such circumstances and endeavours to make use 

 of them. 



A perpetual source of entertainment and reflection is derived from 

 the Fishes of the ocean; their presence frequently furnishes employment, 

 their absence a subject of meditation. In some voyages, toward the 

 Southern Ocean, vast shoals of them are seen, while in others scarcely 

 an individual is met with. This circumstance would lead us to suppose 

 that they exercise some caprice in the choice of their haunts ; yet a better 

 acquaintance with their instincts, habits, and modes of life, might con- 

 vince us that the whole is regulated by the most perfect order. In 1810, 

 when outward bound, the Packet was becalmed near the line, for fourteen 

 days, during which we perceived few fishes about us ; when we caught 

 the south-eastern breeze, and began to move through the water, a shoal 

 surrounded us consisting of more than two hundred individuals, Dolphins 

 and Bonitos, which continued their course in the greatest harmony among 

 themselves and with a speed regulated by our own, from five to seven 



