( 133 ) 
brass cover of the condenser to earth was connected to the tube a, 
and then the beakers B, B, B; B, were mounted in their places 
and together with the supporting-board Ly suspended to the cover 
by means of Zo. 
Into the cock-box S, we place the cock-piece of wood Sj ; this fits in 
it first by means of the caoutchouc-packing Mi, which serves only 
to prevent the gas from taking the way upwards and also by means 
of the caoutchouc-packing 4/3, which is compressed by the screws 
S, till an air-tight fit has been obtained. In the cock-piece the 
supply-tube a and the glass cock-tube p !) are also introduced. The 
design of the cock is for the rest exactly like that of ’94 (see 
also Maruras l.c.). At the lower end of the glass tube p a hexagonal 
brass cap has been cemented, in which is a nut, turning together 
with the glass tube p and ara on to the ae cock-piece hy 
which contains the washer. When the washer has been screwed on 
sufficiently, the hexagonal portions of nut and cock-piece are fixed 
together by means of a hollow hexagonal piece. Then the tubes a 
and p are fixed hermetically into M/ with elastic cement. The pin 
v is moved by a wooden stem Az, ending at the upper end also in 
a pin, which goes through the packing /s. Sideways a tube j is 
placed, serving to test the cock for leakage of the packing 4} and 
to lead away the gas possibly escaping at high pressure through that 
packing, as otherwise the glass tube p' might burst. It is very con- 
venient that the cock-piece with the cock can be taken out of the appa- 
ratus, if the packing, the filter or one of the tubes has gone wrong. 
By pressing the packing Aj by means of the screws Ns between 
the flanges of the cover NW, and of the boiling-case Ny we obtain an 
air-tight fit of the cover on the case. The conical ring Z4, supported by 
felt, guides the ring Zs when the boiling-glass is lowered into the case, 
until through the fitting of the ring Z3 into another similar ring fastened 
into the bottom of the case a centric and elastic mounting is obtained. 
The case itself consists of two thin copper cylinders strengthened 
by rings, the lower and somewhat narrower of which cylinders, Us 
has been soldered excentrically into the bottom U; of the upper and 
somewhat wider, U). A sufficient rigidity in the connection of both 
cylinders has been secured for by inner strengthening-bars Uj. 
The case carries at the upper part two circular and at the lower 
part two oval opposite flanges A; and A, on to which the observing 
and illuminating-tubes are ciamped air tight by means of flanges 
1) Constructed exactly like the cock, depicted Pl. [ Comm. N°. 52, where the 
drawing is more distinct, 
