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Ermann] a series of determinations from 1845—1846 by the
Pulkova astronomers Schumacher, Forth and Moritz.
They found 1
the linear coefficient of dilatation of ice = O.00000424 (Schumacher)
’ ■ » » > » > — 0.00006387 (Porth)
» > • > » » > = 0.00006469 (Moritz)
The coefficient of cubic dilatation of the ice was determined
by Brunner2
coefficient of cubic expansion of ice — 0.000113
This number is decidedly too small. More exact
determinations on pure ice were made in 1852 by Pliicker and
Geissler.3 The average results from 4 series of experiments
executed with dilatometers of diminutive size but admirable
workmanship were:
1) coefficient of cubic expansion of ice = O.000155
2) > > » » » — 0.000153
3) > > » ■ » » = 0.00015G
4) * » » , . > = 0.000170
Pliicker and Geissler concluded from their experiments,
that the coefficient of expansion by heat of pure ice
is.constant and its dilatation regular at all temperatures (from 0°
unto —20° or —24° C).
In 1879 the author, in company with H. Larson4, tried
to trace out the curve of volumes of the ice for every
centigrade from 0° to — 12°.75 C. We found it easy to verify, that
the average coefficient of expansion given by Plücker and
Geissler was right, but we found serious reasons to doubt,
that the dilatation of ice was uniform. On account of the
imperfect construction of my dilatometer at this time and in
want of a balance adapted for exact weighing of great
quantities of mercury, we were obliged to postpone the verification
of this observation.
In the following it will be shown, that we were not
mistaken, though we then considerably overrated the irregularity
of the dilatation of the ice.
But we certainly did not then expect to find, that the
1 Recueil des Mémoires des Astronoms de Pulkowa. 1853.
3 Ann. chim. et phys. (3) 14. (1845).
:i Pogg. Ann. LXXXVI.
1 Ofvers. K. V. A. Forhandl. 1879.
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