287 
tion of the five years, adopting 5° C. as the lower limit of useful 
temperatures, with the following results: 
Sums of mean daily temperatures, less 5° OC. and rejecting negative remainders, 
from December 1 up to the dates of flowering and of harvesting. 
Rye. Winter wheat. 
Year. Flower- | Harvest- | Flower- | Harvest- 
ing. ing. ing. ing. 
PRS eee vie ore ee 537 1,113 | 730 1,235 
SS eee ee oan caw os oe bas oo ess ecSoccsceu oe 602 1,180 793 1,311 
TEED Lo ok Bare acl 496 1,0%5 720 1,271 
1GSD 2 22ee es eee See ee ee ee ae ae 460 1,076 638 1,248 
TRE! oh eas 527 1,089 727 1, 268 
[ite bonne Se ee, Ste ae a eee ee ae ee ee 469 1,047 686 1,245 
AVEO ieee eee oe ee ee eae See eee Se eee | 515 1,096 | 716 1, 263 
The differences between the numbers for flowering and harvesting 
show, as in previous years, that although winter wheat requires more 
heat (716° C.) to bring it up to the flowering point than does rye 
(515° C.), yet after having attained that point the wheat requires 
less heat (547° C.) than does the rye (581° C.) in order to ripen the 
grain to the harvest. This fact, which has shown itself in each of 
the six years, can be considered as well established. 
The harvest of spring barley.—The dates of harvest are, as before, 
reduced to sea level by allowing for retardation at the rate of four 
days per 100 meters. The sums of mean daily temperatures, less 
5° C., counting from the 21st of March, which is the mean date of 
sowing, and up to the date of harvest, are given for each year in the 
following table: 
Spring Spring 
ela a Pcntad 
arves . arves 
Year. sums of Year. sums of 
tempera- tempera- 
tures. tures. 
Of oT; 
IRS) Se OE ei ie 0 a Or NOt | LSS ee a eee ee ey eee 1,083 
NSS hentai Nas eo eee ete esa SDP T ST ())) | BSA Se See ek es Re 1,049 
LSS 2 ree aerate at ere oe 2S et oe te OSH Pl SBb een wes se seen WS. St eee 1,042 
The general mean for these six years is (within the range of 
its probable error) the same as the corresponding figures for 
winter rye. 
In a fourth memoir, Angot (1890) gives similar computations 
for the harvests of 1886 and 1887 in France, the number of stations 
being now appreciably larger than in the preceding years. A new 
computation of the retardation due to altitude gives him 3.7 days 
per 100 meters for the llac, 4.0 for the chestnut, 3.7 for the elder, 
