Af/1'icultural Mcteorolof/y . 
319 
Contigrailo, which, multiplied by 120 days, would pivo 2004°. 
This would correspond to a daily heat of 62*06° Fahrenheit. 
Both Boussingault and Gasparin conclude that the range marked 
by the thermometer in the open air is insufficient to produce an 
amount of caloric accordant with what they deem requisite for 
the maturity of the crop. They adopt, therefore, a supplement 
of solar heat, distinct from, and in addition to, the observed tem- 
perature of the air. But this latter element does not seem to 
have been so accurately calculated or so clearly defined by them 
as to enable its truth as a rule to be tested by its application to 
other countries and climates. Although the subject is treated at 
some length, the tables appended do not distinctly give the mean 
atmospheric temperature for each month, together with the 
ascertained amount of solar heat, and the additions to be made on 
that account. Nor do the tables appear perfectly consistent 
either with each other, or with the calculations based upon 
them. 
Assuming, however, that wheat begins to vegetate afresh when 
the medium temperature of the spring advances to 42*8° Fahr., 
J\J. Gasparin tells us that that point is reached at Orange on the 
1st of March, and at Paris on the 20th ; and that the harvest 
takes place ordinarily at Orange on the 25th of July, and at 
Paris on the 1st of August : that is, respectively in 1 17 and 132 
days' growth. According to M. Gasparin, the plant has received 
in that interval the following quantities of caloric : — 
At PARIS. 
At ORANGE. 
Centigrade. 
Fahr. 
Centigrade. 
Fahr. 
.Monthly 
Mean 
Solar and 
Atmospli. 
Total. 
Montlily 
Mean. 
Montlily 
Mean 
Solar and 
Atmosiih. 
Total. 
Monthly 
Mean. 
March (10 days) 
April (30 do.) 
May (31 do.) 
June (30 do.) 
July (31 do.) 
o 
I0-9 
1.5-8 
18- 7 
19- 3 
22-3 
o 
109 
474 
579-7 
579 
t>91 
o 
51-62 
60-44 
6:r66 
66-74 
72-14 
March (31 days) 
April (30 do) 
May (31 do.) 
June (2 5 do.) 
o 
16-7 
19-3 
•22-3 
27-2 
o 
517-7 
579 
091-3 
680 
o 
62-06 
66-74 
72-14 
80-96 
2,43-2-7 
2,468 
Although this table (which is extracted from vol. ii. p. 87) 
does not bear on the face of it any discrepancy, yet it is impos- 
sible to arrive at the results it presents by merely adopting the 
data as given at pp. 77, 78, on which it professes to rest. M. 
Gasparin there gives certain monthly maxima and minima of 
atmospheric temperatures observed at Paris, Peissenberg, and 
Orange, as well as augmentation due to solar heat alone, but un- 
