OF CUBICAL EXPANSION OF ICE. 
471 
Deso'iption of Api^aratus. 
Fig. 4. 
(-1 size.) 
The vessel wliicli constituted the reservoir for the liquid used in the hydrostatic 
balance is shown in section in tig. 4. It consisted of a funnel-shaped vessel, A, of 
cast iron. This was turned up in a lathe, and care was taken 
to have the inside surface quite free from “ lilow-holes.” 
Into this vessel at B, a tube of steel, N, was driven. The 
lower end of this tube carried a tightly-tittiug screwed piece 
C, the bottom of wliicli wms closed, exce 2 )t for a central bole 
about '4 millim. in diameter. This hole was for the wire to 
})ass through doiviiwards to srqiport the scale pan, and 
upwards to tether the vessel which held the ice or water. The 
vessel shown in fig. 4 may be called (to save circumlocution) 
the funnel. 
Tlie top of the funnel could be closed liy an accurately 
fitting steel circular plate, shovui in section as D. In order 
to fasten this plate dowm securely on to the top of the funnel, 
a three-armed piece of iron, shown in fig. 5a, was used. This 
was provided with three scinws, E, the lower ends of which 
bt)re directly on the circular plate D, immediately over the 
annular plane-bearing surface, F. A central screw, G, with G 
a milled head, served to hold the plate L) in position in some manipulations which 
did not require that the surfaces at F slujuld fit very closely. The three-armed 
})iece was provided with three stout pegs, one of which is shown as H in fig. 5h, 
which is a section of one of the portions of the tri-radiate clamp of which fig. ba is a 
plan. These pegs could traverse round the channel, I, fig. 4, and their pressure on 
5a 5b 6 7 8 
(I size.) (I size.) (f size.) (5 times size.) (f size.) 
the upper roof of this channel, provided reactions for the pressure of the four screws 
E, E, E, G. In order to place the tri-radiate clamp in position, tliree small gaps 
were cut at angular intervals of 120° in the outside of the top rim of the funnel, and 
three similar gaps w^ere provided in the plate D. 
