64 
earth. The following table gives the mean temperature for the ten- 
day periods ending on the dates given in column 1 and at a depth 
of 1 foot below the surface of the ground. Temperatures are given 
by them for other depths, as also for the air; the total rain and snow 
is also given. An investigation of the connection between earth 
temperature and the development of vegetation is being carried on 
by them, but as no results have as yet been published I give merely 
their soil temperatures at a depth of 1 foot, which usually agree, 
within a degree centigrade, with the average temperature of the air 
for ten days. 
» 
Mean temperature of the soil at a depth of 1 foot for periods of ten days at 
Montreal, Canada. 
Average Average | | Average 
End of period. pee End of period. Seal End of period. eee 
tures. || tures. | | tures. 
1888. °c. || 1889—Continued. °C. || 1890—Continued. ous 
November ills 22. -=- G53)||te yn Ohne emne eee 2. 1) Mare hiG Seen eee 1.0 
November 21 -...___.. P| (icc va eee ee 20.4 || March 16._........-.- | 0.7 
December 1 ._-_-2.._.- 0.4 | Sly 20 eee eee ee #15 \) Marchi26=-------2--= » Oe! 
December 11-__._.__-- 0.9 ! INU UST Obese ae eee 21.2 | TA Dri bse eo oe | 0.5 
December 21_-__.___--- 0.8 | PASO US tal Sees UR (il) PeMopiall | aye eee ae | 0.6 
December 31___..-__-- 0.4 | ATI OUSt eee eee 18.9 | (Aprilia 5.3 
1889. | September 7_.......- 19:6/|| Many <= etsce Greer | 7.4 
joa 0.5 || September 17 __.____- TSh4s |e Mica 5 9.1 
January 20_....___..- 0.6 || September 27 ----...- 13.6 | Maiyi2b 22 as oe eee 11.7 
January 30__......-..- 0.2 | October ees 11.0 | june 4. ae 15.0 
February 9 __....____- 0.2 || October 17 -_.--.-_..- Gell) Jum 14S eee 15.5 
February 19 __.._.___. —0.4 || October2ije22== == aD) li Afebaveny Boe eee eee 17.6 
Wimedh i hia November 6 _.-.----- 4.7 || July 4 i ale ere eee a 21.1 
Weel SO _0.3 || November 16 =... .--- AP Saliva doe sees eee cee 20.7 
Machin ieee ae | _0.2 | November 26 _----__- BRON gO livse4 ae eee eee meee 20.7 
Wim 0.5 || December 6----..---- 12h PAu cuShioesasnse- =e 21.7 
Worl te. fers | aia | December 16____---.- 1.0 | AUgUStl S=ees-===——es | 21.9 
(April oOc 228. oe | 3.7 || December 26 --_------- 0.9 |, August 23 = Seer 18.7 
PACD rat ee ee a eee Gat 1890. | | September 2 ---.--.-- 16.5 
Mia viel eee ee 12M aU aIsy; Dae eo ae | 1.3 || September 12 ________ 17.2 
May 20 eas soe see 15.3 || January 15_.__--..--- 1°9 |! September 22 -------- Bet 
Maysc0 pete 22 | 14.7 | January eee 1.4 October a mista pgs SOS M1 
JUNO PEs Se Nee | 15.5 | February =2:--=---- | yea f | October 12 -__.-----_- 10.1 
SUMO see maaan a | 18.8 || February 14 _...-..-- | 0.8 | eda Seaatae= a 
June 29. -..----.-------| 19.2 Hebruary 24 = oe: | 0.8 | OnVGMMIS SYNE aaa sc2 a5 : 
| 
This series seems to show the powerful influence of a snow covering 
to keep the ground from cooling to very low temperatures during the 
winter. The minimum temperatures at 1 foot depth were —0.5° F. 
during the twenty days March 22 to April 10, 1889, and +0.4° F. 
during the ten days March 17 to 26, 1890. 
