2 
_ itis necessary to take into account ak temperature peculiar lo the latitude 
[ 300 } 70 | ‘ 
itself, andthe reduction caused by elevation. 
e decrement of ¢aloric, as we ascend into the air, will be understood __ 
by the following ine calculated by Daniell, from observations made by 
Mr. Green, the a onaut, i in an aerial voyage performed in 182 821. These 
are particularly | pens uctive ; because they were all made within the space 
of half an hour, under circu umstances which varied as little as possible. 
The —, . the surface of the earth was - elon Ly 
t an elevation of 2,952 feet, edi ee = ae 
7,288 ° - $72" 4 
9993 ae See ae 
LEOSD a Fee wae! es,  a5° 
11,293 - i he 
The difference between the temperature of the highest sinh aes the 
earth’s orale apenanag to 36° in the space of twenty-sev ven mi 
‘The amount of the decrement of heat, as compared with cag of ade, 
has ey tank to be, in France, equal to one desire ms a 
Jatitude for every 540 feet of vertical elevation ; that is t , the temper- 
ature of a distriet of 3,240 feet of elevation, in 45° north jeuiindo, dite be 
equal to the temperature of 51° north latitude on a level with the sea. ,But, 
t,nearer he squalor salen ee 
tion varies. He found, from careful and repeated o 
3,000 feet of elevation, ‘that, in the middle of the aun zone, ree mean tem- 
perature of the year decreased ina degree equivalent to 2° et north inate 
for every 600 ree of eupaaeny the mean summer heat, 1° 30’; the mean 
autumnal heat, | ; OF, “aly avera 
was about 1° of uinae ee pr 396 feet of elevation. Temperature de- 
creasing in this rapid ratio, it is evident that, if vegetation is affected by 
ascent of a mountain. 
sth pt at by the following fables, that » 
e limits at which plants grow, 
ae tbe, mountain, teal plants en- 
eng 
oud en met eaaile ei 
. —- for a subsi and, hae renter th ere nor rtheirbabits will enable t 
* H.P 
i. in the 0 yo ‘of valuable vegetables. 
—In the green- mone s nd hot-houses of he Norther United se and f Northern 
Beas there are hundreds of very valuable cegttanhea which s serve as, merely 
chee of ai sachets to their own ers ; bat which, one Ahi ‘5 mes Flor 
po fon, and to all: the'eiyiti 
a ee. 
Nore.—All the coffee of America procecds fr from ii bi vaden 
plants in Paris; and the subser hee id ‘atti Plant brought from hi ga 
is mOW expecting, w ekls f eae Spey he : 
“suckers of the Musa Abaca : or Manilla hemp yenine a ease ei OH ie 
- : eee atta 
