20 | 
On Aérostation. ET 
because I conceived that new methods are entitled to no consi- 
deration unless they are shown to be adequate to their end, and 
necessary, on account of some imperfections in the means pre- 
viously employed. The advantages to be derived from the pro- 
cess now proposed are the recovery of the whole of the silver, 
the purity of it, and the little time and trouble required for the 
operation. 
XLVI. On Aérostation. By A CorresPONDENT. 
To Mr. Tilloch. 
Sir, — aes enthusiasm excited by the first invention of bal- 
loons, has like all the other movements of enthusiasm produced 
a reaction, which has hitherto involved in a kind of ridicule 
every attempt to apply them to any useful purpose, and which 
has been fatal to any progress in their improvement. The steady 
march of the human mind, however, ultimately triumphs over 
these alternate fits of extravagance and torpor ; and the day is 
probably not very distant, when the theories of ingenious men 
controlled by the sober experiments of science will lead to more 
happy results. 
The weight of the machinery necessary to give a mechanical 
impulse to balloons, appears to be an insurmountable obstacle 
to that mode of couducting them ; and the inclined plane lately 
recommended by your ingenious correspondents is liable to the 
same objection, and perhaps in a still greater degree. 
Methods must therefore be devised of rendering the atmo- 
sphere subservient to their motion and guidance as well as to 
their support. The contrary currents of air that generally take 
place at different elevations are well known; and it is presumed 
that if the balloon were retained near the upper confine of one 
Stratum, and if a smal] auxiliary balloon were attached by a rope 
and permitted to ascend into another stratum, the velocity of 
the former would be sufficiently retarded to admit of its being 
steered in a course inclined by several degrees to the direction 
of that current in which it floated: much in the same manner 
that the skilful seaman drops his vessel down a strong tideway, 
by giving her a slight velocity in the opposite direction, which 
enables him to’sheer and sicer her at pleasure. 
Or, on the contrary, the auxiliary might be made to descend 
in search of a proper resisting current of air. 
If the stratum should be too extensive to push the auxiliary 
beyond its limits, even then the diminished rapidity of the wiad 
at a great elevation would probably produce a sufficient we, 
a 
