175 
needed for ripening the crops of the varieties of wheat ordinarily 
cultivated in Normandy, as shown in the following table: 
Sums of daily temperatures. | 
Date of sow- | Date of har- | From inean 
ing. vesting. sowing | arito| Total. 
to ae harvest. 
SHG Of Ge 
Nov. 17,1869 | Aug. 12,1870 356 | 2,000 2, 356 
Nov. 5,1870 | Aug. 20,1871 359 | 2,158 2,517 
Nov. 27,1871 | Aug. 4, 1872 395 1,914 2,309 
Nov. 5,1872 | Aug. 3,1873 632 1,806 2,438 
Nov. 27,1874 | Aug. 10, 1875 6 339 1,880 2,219 
Noy. 4,1875 | Aug. 3,1876 490 1,828 2,318 
Nov. 18,1876 | Aug. 2, 1877 701 | 1, 769 2,470 
Dec. 6,1877 | Aug. 7, 1878 367 | 2,085 2, 402 
Dec. 21,1878 | Sept. 1, 1879 171 | 2,085 2,256 
Average, 
INOVvaliee-.| MuesSeec.- = 455 | 1, 924 2,379 
By similar calculations Hervé Mangon obtains for other crops as 
cultivated in Normandy the following results: 
Mean date. Sums of 
= daily 
temper- 
= : mune 
aes arvest-| from 
Sowing. ing. sowing 
to har- 
vest. 
ve 
DCL 
(Giri ies wet ee ee ees a ee eer ae Mar. 7 | Aug. 5 1, 826 
IDO ese ge Sots oe eres ee ae See ee eg ee ee eee Nov. 8 | Aug. 20 2,197 
[Barloyvprs peer ree oes Ao ed See ee Coke ei kee eee Apr. 13 | Aug. 18 1,810 
TENSIVE) <a ee ak URE Se eR Re AS a ee Mar. 3 | Aug. 25 2,210 
RSC Kawi Gate see ee ae ee ees ees see le Bee a oo eeaeaaa June 10 | Sept. 10 1,525 
Hervé Mangon concludes his essay with two important practical 
rules, deduced from his data relative to the climate and crops of the 
department of La Manche: (1) In a mild and uniform climate, like 
that of the northwest of France, there is always an advantage in 
sowing the seed early in the autumn; (2) by computing annually the 
sums of the degrees of temperature observed since the date of sowing 
and by consulting the numerical tables given in this memoir one can, 
with great accuracy, calculate four or six weeks in advance the date 
of the approaching harvests of the respective plants. 
The tables given by Mangon for his locality can be reproduced for 
American stations wherever the meteorological observations and the 
dates of planting and harvesting are recorded; although it may be 
possible to consider more minute details of climate and soil than he 
has done, yet the success attained by him in his elementary collation 
of fundamental data must stimulate to similar work in this country. 
