Wilkins' Improvement of Moth's Apparatus. 389 
nozle may be fitted on with many apertures in it (as in a 
water pot) to divide the stream of air ; or a small piece 
of gause or silk of very loose texture may be tied on in 
form of a globular bag at the end. Such a piece will be 
necessary even over the nozle, tied at a small distance in 
advance : for when water is forced into the superior part 
of the machine, as is frequently the case, it stands above 
the arch of the * siphon, and if at that time the pressure 
from below relaxes by the absorption or escape of air and 
the cessation of discharge, the pressure from above 
would be liable to force some of the water through the 
siphon into the lower part of the machine ; this will be 
prevented by the little bag before mentioned, pressing in- 
to the tube, or applying itself over the holes in the nozle, 
but would never, if properly put on, and sufficiently open, 
obstruct the air coming out, as it would then be distend- 
ed. It would be advisable to have about two inches of 
the long end of the siphon separate, and cemented into 
the lower part or place of the old valve, as a receptacle, 
and fitted there, that the rest might be removed and clean- 
ed (if silver), and if the siphon is made of glass, it 
would be best to have a silver receptacle. Many old 
machines with bad valves or none, may be repaired by 
passing the long leg of such a siphon through a cork, and 
fixing it in the old aperture for the valve : some might 
prefer this method in new machines, and have a glass 
stopper at that part to receive the siphon (as shewn in 
the plate.) This would be more costly and liable to ac- 
cident, though somewhat easier to inti ode ce the siphon. 
In the other plan it must be introduced above, with a pair 
of forceps. Water may be impregnated in a much shorter 
* This elevation of water will often return, if the upper stopper is very tight, 
and the bent tube attached to the upper part of the machine is so long as to en- 
ter the main body of water. It would therefore be as wdl to have it something 
shorter, in new made machines . 
