196 J. P. Cooke, Jr., on Lecture Experiments. 
to steam fitters as a “return bend.” Any machinist will easily 
adapt this casting to the required use by attaching to it, as shown 
in the figure, a circular iron plate to serve as a stand, by also 
screwing on to one side an or- 
dinary “elbow joint,” and at the 
same time by carefully rimming 
out the three apertures so as to pre- 
sent smooth surfaces for the ad- 
hesion of the rubber stoppers. 
Into one of the openings of the 
“return bend” we fasten with a 
7. 
for a stop cock so well known to 
chemists as a nipper tap. Last of ee 
all we obtain from the glass house ‘ 
a tubulated tube like that shown in fig. 8, of 
such size that it will cover the eudiometer tube 
u 
the wires of the eudiometer, pass between the stopper an the 
for atte ie tubes.* These rubber joints, if well made, g1V@ 
great flexibility to the apparatus and enable it to withstané 
quite rough usage. 
_ eudiometer being thus mounted, mercury is first poured 
_mereury transferred by inclining the apparatus to the 
closed limb, this process being repeated until the eudiomete! 
Place around the upper end of the eudiometer tube a rubber 
sufficiently thick ‘fill the annular space when the ee 
also perforated with a number of small holes, so that (0° 
he experiments, may pass freely. This ring confines. 
‘greater solidity to the apparatus. 
