20 F. Gardiner on the ice in Kennebec river. 
Art. IL—On the Ice in Kennebec River; by Rev. FREDERIC — 
GARDINER, : 
THE following observations were made upon the ice on the — 
Kennebec river during the months of February and March, 1865. — 
The location isin the town of Gardiner, at a point where the © 
river is about 700 feet wide. The water is entirely fresh for 
many miles below, and the average ebb and flow of the tide 
here is five feet. The depth of water varies, according to the — 
state of the tide and the particular locality, from 17 to 25 feet. — 
In the course of the winter the ice is always observed to crowd 
ashore, crumpling up in ridges on the flats and near the edge of 
the channel. This process was already well advanced when, afte: 
. 
ter © 
various delays, these observations were begun, Feb. 6. A row 
of stakes was planted in the ice, by boring holes quite through 
to the water, at distances of about 100 feet apart, avoiding a © 
very near approach to either shore. Their positions were deter- — 
mined by observing the range of each with a near and a distant © 
fixed object on the shore, by means of an instrument with a 
small telescope, and also by the angles subtended at each posi- 
tion by fixed objects on the opposite shores. After an interval 
time, the instrument was placed in the same range, and the 
distance from it to the stake measured. The stakes were soon — 
broken off even with the ice by boys, and then a heavy snow ~ 
fall vith the consequent sinking of the ice and formation of a 
separate sheet of ice above, with water between and slush above, 
made it impossible to recover the ends of the stakes until March 
18th. The distance between the eastern and western stakes was 
500 feet. March 18, the easternmost stake was found to have ~ 
moved to the eastward 122 inches. A stake 200 feet west of — 
this had not sensibly changed its position. The western-most — 
stake had moved to the westward 12 feet 2in. There was thus a 
total expansion of the ice of 13 feet 22 in. in a breadth of 500 
. 
feet, 0 
is entirely independent of the action of gravity, and is 
due to variations in the temperature of the air, that of the water 
having been nearly constant, as will be seen below. It is to be 
regretted that there are no data for determining the 
of this motion in successive proportions of time—a defect which 
it is hoped the observations of another winter, and of observers 
in other localities, may supply. The temperatures observed at _ 
my house, 120 feet above the river, during the time, are as fol- _ 
lows, in degrees Farenheit: Mean temperature, Feb, 6 to 28 
inclusive, 22°37"; mean of extreme heat of each day, 32°; mean _ 
of extreme cold, 12:74°; mean diurnal variation, 20-217°: ex- 
t } . 4 sees 
e heat, 45°; extreme cold, -17°; extreme variation, 62° | : 
per cent nearly, in 40 days. Of course this motion © 
proportion — 
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