Balloon, if we may so call it, in the model) is calculated to
encounter in proceeding _endways_ through the atmosphere is only
_one-sixth_ of what a _plane_ or _flat_ surface of equal area with its
largest vertical section, would experience at the same rate; while the
resistance to the progress of a globe, such as the usual Balloon, would
be one third of that due to a similar circular plane of like diameter:
shewing an advantage, in respect of diminished resistance, in favour of
the former figure, to the extent we have above described; an advantage it
enjoys along with an increased capacity for containing gas--the cubical
contents of an ellipsoid of the proportions here observed, being exactly
double of those of an ordinary Balloon of equal diameter, and
consequently competent to the support of twice the weight.

Independent of the advantage of reduced resistance in this form, there
is another of nearly, if not quite, equal importance, in the facility
it affords of directing its course; an object scarcely, if at all,
attainable with a Balloon of the usual description however powerfully
invested with the means of motion; as any one will readily perceive
who has ever noticed or experienced the difficulty, or rather the
impossibility, of guiding a tub afloat in the water, compared with the
condition of a boat or other similarly constructed body, in the same
element. The efficacy of this provision and its necessity will appear
more forcibly when we observe that whenever the Balloon in the machine
here described is thrown out of its direct bearing by the shifting of
the net-work which connects it with the hoop, or by any other accident
whereby its position is altered with respect to the propelling power,
its course is immediately affected, and it ceases to progress in a
straight line, following the direction of its major axis, unless
corrected by the intervention of a sufficient rudder.

The second object, after establishing a proper form for the floating
body, was to contrive a disposition of striking surface that should
be able to realise the greatest amount of propulsive re-action, in
proportion to its magnitude and the force of its operation, which it
is possible to accomplish. To shew by what steps and in consequence of
what reasoning this point was determined as in the plan adopted, would
occupy considerably more space than the few pages we have to spare
would admit of our devoting to it. Suffice it to say that of all