by foolish action invite disaster. This
is true of aviators the same as it is of railroaders, men who work in
dynamite mills, etc. But in nearly every instance the responsibility
rests with the individual; not with the system. There are some men
unfitted by nature for aviation, just as there are others unfitted to be
railway engineers.

CHAPTER XVI. RADICAL CHANGES BEING MADE.

Changes, many of them extremely radical in their nature, are continually
being made by prominent aviators, and particularly those who have won
the greatest amount of success. Wonderful as the results have been
few of the aviators are really satisfied. Their successes have merely
spurred them on to new endeavors, the ultimate end being the development
of an absolutely perfect aircraft.

Among the men who have been thus experimenting are the Wright Brothers,
who last year (1909) brought out a craft totally different as regards
proportions and weight from the one used the preceding year. One marked
result was a gain of about 3 1/2 miles an hour in speed.

Dimensions of 1908 Machine.

The 1908 model aeroplane was 40 by 29 feet over all. The carrying
surfaces, that is, the two aerocurves, were 40 by 6 feet, having a
parabolical curve of one in twelve. With about 70 square feet of surface
in the rudders, the total surface given was about 550 square feet.
The engine, which is the invention of the Wright brothers, weighed,
approximately, 200 pounds, and gave about 25 horsepower at 1,400
revolutions per minute. The total weight of the aeroplane, exclusive of
passenger, but inclusive of engine, was about 1,150 pounds. This result
showed a lift of a fraction over 2 1/4 pounds to the square foot of
carrying surface. The speed desired was 40 miles an hour, but the
machine was found to make only a scant 39 miles an hour. The upright
struts were about 7/8-inch thick, the skids, 2 1/2 by 1 1/4 inches
thick.

Dimensions of 1909 Machine.

The 1909 aeroplane was built primarily for greater speed, and relatively
heavier; to be less at the mercy of the wind. This result was obtained
as follows: The aerocurves, or carrying surfaces, were reduced in
dimensions from 40 by 6 feet to 36 by 5 1/2 feet, the curve remaining
the same, one in twelve. The upright struts were cut from seven-eighths
inch to five-eighths inch, and the skids from two and one-half by one
and one-quarter to two and one-quarter by one and three-eighths inches.
This result shows that there