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. FE re ee OE Pe PRR eT Le ae eee 
F. Gardiner on the ice in Kennebec river. 21 
March 1 to 18, inclusive-—Mean temperature, 33° _ ; mean of 
extreme heat, 41°33°; of extreme cold, 24°944°; mean diurnal 
variation, 15°44° ; - extreme eat, 50°; extrem e cold, T° ; extreme 
variation, 43°. These temperatures, of course, are each that of 
the shade ; they would be much increased by ‘taking into con- 
sideration the influence of the sun to which the ice was expose 
When the ends of the stakes were recovered, they were float- 
ing in greatly enlarged holes. The stakes were pieces of pine 
turned, 2 in. in diameter. They were placed in holes of 14 in. 
diameter, and frozen in firmly. When found, the holes varied 
from 14 to 64 in. diameter. his fact probably accounts for the 
anomalous temperatures given below, and must be due to the 
action of the sun’s rays in the substance ‘of the ice absorbed by 
the wood of the stakes. It also illustrates the effect upon the 
ice of objects within its substance. The larger holes were in 
the middle and near the eastern side of the river; the smaller 
were toward the western shore, where a high bank cuts off the 
sun early in the afternoon. 
The subjoined temperatures of the water and ice were taken 
with thermometers enclosed in cylinders of pine of such size 
as to leave a minimum thickness of 4in. of wood outside the 
bulb. The piece of wood covering the graduated side of the 
stem was confined only by an india rubber ring which could 
be slipped off in an instant. These thermometers were made 
by Green of New. York, accurately graduated to »4° C., an 
easily read to z5°. The ‘tem. mperatures of the air and snow were 
observed with ed sbaniainasiie: The minimum time of ex- 
posure in each case was a half hour, and it was not found that 
a. longer exposure produced any change, although an hour was 
repeatedly tried. The thermometers were sunk perpendicularly 
in the ice, by boring holes with an augur a trifle larger than the 
thermometer cases, sed after inserting them, stopping the top 
of the hole with dry snow. The measurements, in alle are 
to the center of the bulb, which was about 1h i in. long. The 
temperature of the water was always observed near the bottom | 
of the e river, and also immediately under the ice; but no differ- 
ence was observed except on Feb. 6, when the water near the 
bottom was 0-10, and just. below the ice —0-05, the ice at the time 
wasting a little. Feb. 15, 0°10; Feb. 22, 0-15; March 11, 0:35; 
March 18, after a heavy rain, producing a freshet and the 
river with melted he 0°15. This freshet terminated ‘lan ob- 
servations — the 
Ata t about the middle of the river and near the line of 
the staken phe however, a few feet for each observation, bo 5 
following observations were made: Feb. 6, mean tem 
of air in shade, 0°; depth of snow on ice, 15 in.; “4 
in.; of black ice, 6} in.; total, 13 in.—surface 
