Physics and Chemistry. 119 
sion that the total quantity of water conveyed by the stream is prob- 
ably equal to that of a stream 50 miles broad and 1000 feet deep,* 
size and velocit ty a the stream, 5,575,680,000,000 cubic feet of 
water are conveyed from the Gulf per hour, or 133,816,320,000,000 
cubic feet daily. Consequently the total quantity of heat trans- 
ferred from the equatorial regions per day by the stream amounts 
to 154,959,300,000,000,000,000 foot-poun nds. 
From observations made by Sir John Herschel and by M. Pouil- 
let on the direct heat of the sun, it oe found that, were no hea 
un 
24 per cent. Taking the ° forma estim inte, re 74 aeons rom 
second will therefore be the quantity of heat falling on a square 
foot of the earth’s surface when the sun is in the zenith, d 
were the sun to remain stationary in the zenith for twelve hours, 
‘2 fvtas = foot-pounds would fall upon the surface. 
It can be shown that the total amount of heat received upon a 
unit mii biee on ie equator during the twelve hours from sunrise 
till sunset at the time of the equinoxes is to the total amount which 
would be received upon that surface, were the sun to — in 
the zenith during those twelve hours, as the diameter of a circle to 
half its circumference, or as 1 t o 15708, It follows, therefore, 
square mile 49,636,750,000,000, foot-poun . But this 
amounts to on x part of the quantity of heat daily con- 
vey the tropics by the G m. In other words, the 
am conveys uch heat as is receiv 
ulf-s 
Magica square miles at the equator. The amount thus conveyed 
s equal to all the heat which falls upon the globe within 63 miles 
on each side of the equator. According to calcul ra made by 
Mr. Meech,{ the annual quantity of heat received by a unit surface 
on the frigid zone, taking the mean of the whole poe is 545 of 
* The Gulf-stream at the narrowest place —* by the Coast Survey, and 
the place where its velocity was greatest, was found to be over 30 statute Boo 
an 
warm 
water which is received by the Atlantic from the e equa ator; a great mass of water 
flows into the Atlantic without passing “tins the Straits of Flo 
+ of Ro of Edinb., vol. xxi, 
Trans. y. Soc. xxi, p. 57. Phil. 8. 4, vol. i 36. 
¢ Smi ret Contributions to ‘Kuarieden vol, ix. abies eles 
