aged 
of water except about two inches 
from the brim.. 
Fig. VIII. ‘The board (exprefied 
by @, in Fig. VII.) by itfelf, and 
inverted. It has two funnels hol- 
lowed out on its under-part, which 
is in this figure reprefented upper- 
moit: the orifices of the funnels 
are reprefented by the two round 
holes, one of which muft be larger 
than the other. aa reprefent two 
oblong incifions to receive the ex- 
tremity of the bendedtubes, through | 
which the various. kinds of air are — 
let up into the inverted jars placed 
upon the board. | 
Fig. IX. A cut of the two fun- . 
néls hollowed out in the board, re=_ 
prefented by Fig. VIII. 
