219 
attaching it to the objective on the side toward the refracting edge of the 
prism the lines are seen at once over the whole spectrum. It is import- 
aut, in the case of thick plates, that the surfaces should be parallel. A 
Be eee Se ae Ee ae ae ep a Mee ee ee 
Wiss., xlix. Ww. G 
about 60° C., while that of the other end was above that 
The battery gives a ten times more powerful action than 
antimony element of the same resistance heated to 
xles is easily fused at a high temperature and may be cast in a mould, 
8 place in the thermo-electric ois is then far below that of bismuth. 
worked, must be employed. Pyrolu- 
