OF CUBICAL EXPANSION OF ICE. 
473 
Tlie metliod of holding the funnel during the determinations, and the arrange¬ 
ments for surrounding it with ice or freezing mixture, are shown in tig. 9. 
The tube, C N, of the funnel. A, passed through an Fig. 9. 
india-rubber bung, V, which closed the lower orifice (v ®he.) 
of a large glass jar, W. The funnel was supported 
by a framework of iron, X, which consisted of two 
rings joined by three bent wires. The lower ring 
rested in the concavity of the glass jar and bore the 
weight of the funnel. The jar in turn was supported 
by a larger I'ubber bung, Y, which fitted into a hole 
in the bottom of the lower wooden box, Z. Three 
stout brass jjieces, a, oidy one of which is shown in 
the drawing,, prevented the jar from tipping side¬ 
ways. 
The upper wooden box, />, rested on the lower box, 
Z, while the whole was surrounded on five sides by 
the non-conducting cases, c. These cases were re¬ 
movable boxes of wood loosely filled with cotton 
wool. 
The thermometer, d, })assed through a piece of 
ebonite, e, which rested on the top of the non-con¬ 
ducting case, througli a hole in the case, down a 
wide brass tube,/’, in the upper wooden box, and rested with its bulb in the mercury 
in the collar, K, The removable thin metal vessel, (/, was supported by three lugs, //, 
which were bent over so as to engage the rim of the glass jar. The upper and lower 
boxes w^ere fitted with tlie holes ?, J, which could be closed by bungs. 
The wdiole of the apparatus shown in fig. 9 rested on three levelling screws, wdiich 
in turn were sujjported by a strong table having a hole in its centre through wdiich 
the ware from the funnel passed. 
Tlie lower surface of the low^er Ijox Avas protected from the access of heat by filling 
in the space between it and the table with loosely packed cloth. The description of 
any other parts of the apparatus which may be necessary will be more conveniently 
given Avhen dealing with the conduct of the experiments. 
Deteruiination of the Buoyancy of the UiiihreUa .—In order to find the buoyancy of 
tlie ice and water, it Avas necessary to determine that of the umlirella at different 
temperatures. If Ave knoAv the load on the scale pan necessary to obtain ecpiilibi ium 
Avhen the umbrella only is tending to float in the mercury, then the weights added 
Avheii the umbrella and its contents are equilibrated, gives us the buoyancy of the 
contents. The funnel Avas taken and a thin steel Avire (T7 millim. in diameter) passed 
upAA^ards through the hole o (fig. 4) until it could be threaded through the hole in the 
stem of the umbrella, Avhen it was fixed by tAvisting the end round itself This 
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VOL. CXCVIII.-A. 
