116° Scientific Proceedings, Royal Dublin Society. 
apparatus be attached to a pendulum or pallet arbor, the ter- 
yinals B and C are alternately brought into contact with the 
mercury as the pendulum swings. 
Fig. 2 represents one bored out of a solid piece of glass, the 
action being quite similar. Practicably, by proportioning the 
size of the apparatus, the mercury in immediate contact with the 
glass does not flow at all; but the surface getting more or less 
convex at each side as the pendulum swings, causes the platinum 
point to touch. 
As there is no oxygen in any case, there can of course 
be no oxidation ; and the chance of any variable friction seem to 
be reduced to a minimum. 
New Form of Electric Clock Contacts. 
Mercury in Vacuo, 
Fig. 1. 
