314 Theory of the Pneumatic Parador. 
diameter. On blowing through the tube, strong jets isswed from - 
them, as in similar cases already described. 'T’o one end of the 
tube was then soldered, in such a manner as to offer no obstruc- 
tion to currents of air, a diverging conical tube, as represented in 
the accompanying figure, Fig. 7. 
of which the length was _ cso 
. . SS Se rs aS oe ‘ 
about eight inches; the 
diameter of the smaller 
end was of the same diameter with the cylindrical tube, and that 
of the larger end, one inch anda half. On blowing through this 
compound tube, the flame was drawn into lateral holes made at 
intervals in the conical part, and in the half of the cylindrical 
part next to it, although previously to joining the two tubes it had 
been blown from all the holes in the cylindrical one. It should 
seem, that in consequence of the rarefaction produced in the con- 
ical part, the air in the cylindrical part, meeting with diminished 
resistance to its progress, rushed forward by virtue of its elasticity 
and tendency to equilibrium with a velocity much greater than 
that with which it was expelled from the mouth, and thus became 
rarer and rarer as it proceeded, and more so than the external air. 
Analogous to this effect is the well known fact, that the addition 
of a diverging conical termination to a tube conveying liquids, 
greatly increases the discharge in the open air, though not in an 
exhausted receiver. If the cylindrical part of the compound 
tube be only one eighth of an inch in diameter, flame will not be 
drawn in at any part of it except very near the place of junction, 
nor will it be much affected in any way when held near lateral 
holes in the conical part, more than two or three inches from the 
same place ; within that distance it will be drawn in. 
If we conceive the conical part of the compound tube to be 
flattened in such a manner that the opposite sides may be plane 
and parallel, and to be soldered at the small end perpendicularly 
to the end of the tube, the interior will represent a portion of the 
space between the disks, (the whole of which may be considered 
as composed of a series of flat diverging tubes radiating from @ 
common centre,) with the whole‘of the tube attached. If we 
blow through the tube, the results will be similar to those before 
escribed, except that lateral jets will escape from all holes in the 
‘in consequence of the obstruction the blast meets with at 
