in sq. feet power per lb.
Santos-Dumont.. 350 110.00 30 0.314
Bleriot..... 700 150.00 25 0.214
Antoinette.... 1,200 538.00 50 0.448
Curtiss..... 700 258.00 60 0.368
Wright.....[4] 1,100 538.00 25 0.489
Farman...... 1,200 430.00 50 0.358
Voisin...... 1,200 538.00 50 0.448

While the average supporting surface is in favor of the aeroplane, this
is more than overbalanced by the greater amount of horsepower required
for the weight lifted. The average supporting surface in birds is about
three-quarters of a square foot per pound. In the average aeroplane it
is about one-half square foot per pound. On the other hand the average
aeroplane has a lifting capacity of 24 pounds per horsepower, while the
buzzard, for instance, lifts 5 pounds with 15-100 of a horsepower.
If the Wright machine--which has a lifting power of 50 pounds per
horsepower--should be alone considered the showing would be much more
favorable to the aeroplane, but it would not be a fair comparison.

More Surface, Less Power.

Broadly speaking, the larger the supporting area the less will be the
power required. Wright, by the use of 538 square feet of supporting
surface, gets along with an engine of 25 horsepower. Curtiss, who uses
only 258 square feet of surface, finds an engine of 50 horsepower is
needed. Other things, such as frame, etc., being equal, it stands
to reason that a reduction in the area of supporting surface will
correspondingly reduce the weight of the machine. Thus we have the
Curtiss machine with its 258 square feet of surface, weighing only 600
pounds (without operator), but requiring double the horsepower of
the Wright machine with 538 square feet of surface and weighing 1,100
pounds. This demonstrates in a forceful way the proposition that the
larger the surface the less power will be needed.

But there is a limit, on account of its bulk and awkwardness in
handling, beyond which the surface area cannot be enlarged. Otherwise
it might be possible to equip and operate aeroplanes satisfactorily with
engines of 15 horsepower, or even less.

The Fuel Consumption Problem.

Fuel consumption is a prime factor in the production of engine power.
The veriest mechanical tyro knows in a general way that the more power
is secured the more fuel must be consumed,