safely adopted in
propeller selection. These are: As extensive a diameter as possible;
blade area 10 to 15 per cent of the area swept; pitch four-fifths of
the diameter; rotation slow. The maximum of thrust effort will be thus
obtained.

CHAPTER X. PROPER DIMENSIONS OF MACHINES.

In laying out plans for a flying machine the first thing to decide upon
is the size of the plane surfaces. The proportions of these must be
based upon the load to be carried. This includes the total weight of
the machine and equipment, and also the operator. This will be a rather
difficult problem to figure out exactly, but practical approximate
figures may be reached.

It is easy to get at the weight of the operator, motor and propeller,
but the matter of determining, before they are constructed, what the
planes, rudders, auxiliaries, etc., will weigh when completed is an
intricate proposition. The best way is to take the dimensions of some
successful machine and use them, making such alterations in a minor way
as you may desire.

Dimensions of Leading Machines.

In the following tables will be found the details as to surface area,
weight, power, etc., of the nine principal types of flying machines
which are now prominently before the public:

MONOPLANES.
Surface area Spread in Depth in
Make Passengers sq. feet linear feet linear
feet
Santos-Dumont.. 1 110 16.0 26.0
Bleriot..... 1 150.6 24.6 22.0
R. E. P..... 1 215 34.1 28.9
Bleriot..... 2 236 32.9 23.0
Antoinette.... 2 538 41.2 37.9
No. of Weight Without
Propeller
Make Cylinders Horse Power Operator
Diameter
Santos-Dumont.. 2 30 250 5.0
Bleriot..... 3 25 680 6.9
R. E. P..... 7 35 900 6.6
Bleriot..... 7 50 1,240 8.1
Antoinette... 8 50 1,040 7.2

BIPLANES.
Surface Area Spread in Depth
in
Make Passengers sq. feet linear feet linear
feet
Curtiss... 2 258 29.0