OF CUBICAL EXPAXSIOX OF ICE. 
477 
Fig. 11. 
(1 size.) 
depends on the ratio of the weights, no correction for the effect of the buoyancy of 
the air is necessary. 
The density of water at U° C. was taken as '999884, and that of mercury at 
the same temperature as '135956, wliile the density of mercury at lower temjieratures 
Avas found from the fornuda of Chappuis (‘ Proces-verhaux des Seances du Comite 
International,’ 1891, p. 3 7). The results needed were read olf from a plotted curve. 
The funnel liaAung been filled vlth pure dry air-free 
mercury in the maimer already described, the closing plate 
was removed and air-free water introduced under the 
umbrella. This was accompli.shed liv means of the appa¬ 
ratus shoAvn in fio;. 11. 
This consisted of a glass Indb, J\\ which had a capillary 
tube, I, sealed into it aliove, and which terminated in a stout 
tube, m, below. The whole could he supported by fixing this 
tube in a clamp. A flexible rubber tube, n, communicated 
Av'ith the bulb and Avith a someAvhat larger reservoir not J 
shoAvn in the figui’e. 
iMercury Avas poured into tins resei'Amlr, and it Avas raised 
until the mercury poured out of the orifice, o, in the capillarA" 
tidie, Avldch Avas plunged into a beaker of Avater Avliicli had 1)een kept lioiliug for half 
an hour. The reseiwoir Avas then loAvered, and the boiled Avater rushed into the 
hull), On again raising the reservoir, this Avater Avas expelled, and boiled Avater 
Avas then introduced in its j^lace. This Avas repeated seA-en or eight times, Avhen tlie 
mercury reseiwoir Avas raised and the beaker remoA'ed. The Avatei' spurted out of o in 
a rapid stream, so that no air could pass hack into the Inilh. The point o Avas then 
dipped into the mercury of the funnel, and as tlie Avater was ejected from the capillary 
tulje it floated up and occupied the upper portion of the Inside of the umlirella. This 
Avas kept in position during filling by a set of three stout iron Avires fixed in a Avooden 
l)oard, Avhich Avas fixed on the rim of the funnel so that the loAver ends of the Avires 
pressed on the fiat top of the umhrella. This Avas necessary liecause the umbrella 
Avas only stable AAdren it contained more than a certain quantity of Avater. The 
point 0 Avas so made that although the Avater Avas- projected iqiAvards, the point 
offered no projection for the rim of the umbrella to catch upon, so that Avheu 
sufficient Avater had been introduced, the tube could he remoA'ed. 
The Avater used in these experiments Avas prepared from ordinary distilled AA-ater 
by re-di.stilling in a neAV block-tin still, the earlier products of the second distillation 
being rejected. 
After filling, the funnel and its contents Avere alloAved to cool; the funnel Avas then 
closed Avith the closing plate as already described, and Avas placed in the apparatus, 
fig. 9, the boxes haAung been preAnoirsly Avashed out to get rid of the salt from the 
freezing mixture. The mercury to seal the top Avas noured into tlie collar, and the 
