60 
of the maximum temperatures of the air, less the temperatures of the 
soil at 2 p. m. at a depth of 2 inches was 2.3° F. in July, 1888, and 
3° F. in August, 1888. On the other hand, the average value of the 
maximum temperature of the air, less the temperature of the soil at 
2 p.m. at a depth of 12 inches was 12° IF. for the observations here 
given, scattered through July and August, 1888. 
Temperatures at Brookings, S. Dak. 
[Lat. 44° 20’ N.; long. 96° 40’ W.; altitude, 1,000 feet. ] 
| | Soil tempera- | Soil tempera- 
| es nee nee 
| axi- F Hp. | axi- ane | : 2p. 
|Date,1ee, BBMAIr| eine | M- ‘Date, 1888,|mumair| Saige | ™- 
| ateoe || pent Depth ture. | fll. | Depth Depth 
inches.| inches. hae inches. 
| = ee ten mals ON 
| °F. es || Quake Qin Oy a TE Oge IG A> Hay 
July 18 6010 |W OLGO ses ene ase | Aug. 9 63.0 | 0.0 63 | 60 
l4 81.5 MH iar si We gs 10 60. 0 x (al eee el (OR, 
15 81.0 AO) | peated fe eae | ul 62.0 COW 2. alee ee 
16 2.0) RO ty iis | oer | IR 74.0 10:4 ee 
17 79.0 0 rte | Roe 13 79.0 0:4 ee eee ae 
19 | 86.0 0 Da aca 14 75.0 )) fel eae 
23 82.0 0 BAL sles fe 15 69.0 20 2 ed 
24 83.0 0 Ror ilLer se 16 72.0 0 Tl) eee 
25 82.5 0 ei tee ane 17 73.0 0 12) je ee 
26 89.0 0 ian eens 18 | 82.0 0 ilies eet 
" 88.0 0 iT Nae BE 19 72.0 a (ae Pec 
28 94.0 0 85 67 20 80.0 (OTe (| eames ene ne ee 
29 89.0 0 q 70 21 79.0 | .0 {Oe ee ae 
30 101.0 28 108 76 22 SLO | 4 78 78 
31 73.0 0 87 65 23 EO Oe a ral 
Aug. | 77.0 0 tf 67 24 89:0) 1 20 1) Ky re) 
2» 91.0 0 85 68 25> | hen f94/0P 1) GO alt eHe82 5 
3 | 830] .0 GS ae 70 26 sBL:O8 ee &O'e a] senate eae 
4 89.0 0 85 71 27 89,00)) 0 a) cS4bals ames 
5 7950" || S07 # ee see eee 28 822050420 | <phase 
6 76.0 12 | 88 68 29 94.0 | KO, Giloaeee: aaron 
7 71.0 0 77 67 30 78.0 | | EB ral 
8 76.0 28 | 68 64 31 69.0 | 0 | 83 68 
It would appear that the reading of the soil temperature is fre- 
quently omitted when rain falls; this is a bad practice, but the records 
suffice to show us that in this dry country and during the summer time 
the maximum surface temperatures of the soil will not differ much 
from the maximum temperatures of the air, while the soil tempera- 
tures at 12 inches will closely follow the mean temperature of the 
air. The latter mean, viz, one-half the sum of the maximum and 
minimum record for any day is greater than the mean temperature 
of the layers of soil at 2 and 12 inches depth, as observed at 2 p. m., 
by about 6° F. 
