Remarks on Sir Richard Phillips's New Hypothesis. 35 
tng power. They would keep aloft, and be firm and steady in 
their position under anchorage, even in storms. The large bai- 
Joon described, would pack up when out of use in a chamber 
within the boat eight yards by four, and thus render the ap- 
paratus compact on shore; and in thé atmosphere there is unli- 
mited space to accommodate any bulk with equal ease, especially 
when it is considered that every increase of it implies an increasé 
of levity, and not of weight. Their structure being double, like 
a leathern foot-ball containing a bladder, the thin silken bag of 
hydrogen would not be exposed to any violence; and this gas 
being compressed on all sides alike by the condensed air sur- 
rounding it, would have no tendency to escape, during the ac- 
tion of the wind on the prow, as it would in the case of a com- 
mon balloon, if at anchor or swiftly impelled through the air. 
Danger from fire may be nearly excluded by the proper pre- 
cautions. The same power that creates their progressive hori- 
zontal motion will effect their elevation and depression, by the 
application of an horizontal rudder or sail, and their steerage to 
either side by a vertical one. This will easily be understood 
from the sketch, ‘fig. 2, Plate I. which represents a side view of 
the arrangement of the moving and steering sails of a balloon 
on the wing plan. Fig. 3 represents an end-view of a balloon 
with rotary flyers. Neither of these sketches shows any of the 
connecting parts belonging to their movements, which would 
have made the drawing confused. 
I remain, sir, - 
Your obliged and obedient servant, 
Brompton, May 12, 1817. Gro. CAYLEY. 
ee 
III. Remarks on Sir Ricuarp Purtups’s New Hypothesis. 
By Tuomas Trepeorp, Esq. 
AG He his fabric of the heavens 
Hath left to their disputes, perhaps to move 
His laughter at their quaint opinions wide.”— Milton. 
To Mr. Tilloch. 
Siz, A SLIGHT consideration must convince any person, 
that the phenomena of the universe cannot be the result of any 
continued chain of mechanical causes; and that, ultimately, we 
must arrive at some elements and powers or properties which 
can only be referred to the First Cause, “ which certainly is not 
mechanical,” : 
Reasoning on mechanical principles can be applied only to 
C2 : discover 
