l ( 826 ) 
The mean: 353 gives * = = 279 - 51<Hi a value * hat ‘ S n °‘ 
much smaller than .283.5.10which was obtained by the method 
of the magnetic rise. 
Solid oxygen. 
$ 4. Ellipsoid of solid oxygen. In this case observations had to 
be made directly upon an eliipsoid of oxygen. The oxygen therefore 
had to be frozen in a mould of approximately the same form and 
dimensions as the solid silver ellipsoid described above. This new 
condition necessitated the following experimental arrangement. 
The covet and the Dewar tube are the same as for liquid oxygen, 
with the exception of the cap D. The adjusting tube is also the same, 
but it is so arranged that it can be moved as a whole up or down, 
while the Whole apparatus remains closed and in its place. With 
this end in view it is attached to the tube m, which moves through 
the stuffing-box D \; ! this corresponds to D s of the liquid oxygen 
apparatus, but in this case the wide glass tube C x is lengthened by 
a rigid brass tube M that serves to give sufficient play to the 
vertical movement of-the whole adjusting tube. The former stem k 
had to be lengthened by the same amount {L\ and is contained 
in the tube m. 
The holder is also a glass tube 6"; it is not however closed, but 
at b\ it changes into a very much narrower tube (0.5 mm.) that 
ends at b\ in a glass ellipsoid a". To this ellipsoid there is fused a 
solid stem b\ that connects it with the stretching wire. The oxygen 
gets to the ellipsoid through the holding tube which it enters at b\. 
A rubber tube n (d = 3 mm.) admits'the gas from outside; it is 
attached to the inlet tube ra 4 that passes through the cover and is 
soldered to it. With this arrangement it is easy to cause the oxygen 
to solidify inside the ellipsoid. When the apparatus is ready for use 
the adjusting tube is pulled upwards by the cap A till the glass 
ellipsoid reaches the unsilvered part of the vacuum glass. The vacuum 
glass is then filled with liquid hydrogen. While the ellipsoid is still 
connected with a reservoir of oxygen, the adjusting- tube with the 
ellipsoid is slowly pushed downwards until it does not quite touch 
the liquid hydrogen but is in its vapour. The oxygen is then seen 
to condense slowly, and, if the operation is carefully performed, the 
whole ellipsoid and supply tube are seen to fill with liquid oxygen. 
The tube being lowered still further, vapour is reached that is suffi¬ 
ciently cold to cause the oxygen‘to solidify. On account of the large 
