k and laced above and
below the bamboo ribs which run fore and aft under the main spars and
terminate in a forked clip through which a wire is strung for lacing on
the silk. The tail consists of a horizontal and vertical surface placed
on a universal joint about 10 feet back of the rear edge of the main
plane. Both of these surfaces are flat and consist of a silk covering
stretched upon bamboo ribs. The horizontal surface is 6 feet 5 inches
across, and 4 feet 9 inches from front to back. The vertical surface
is of the same width (6 feet 5 inches) but is only 3 feet 7 inches
from front to back. All the details of construction are shown in the
accompanying illustration.

Power is furnished by a very light (110 pounds) Darracq motor, of the
double-opposed-cylinder type. It has a bore of 4.118 inches, and stroke
of 4.724 inches, runs at 1,800 r. p. m., and with a 6 1/2-foot propeller
develops a thrust of 242 1/2 pounds when the monoplane is held steady.

Bleriot--No. XI, the latest of the Bleriot productions, and the greatest
record maker of the lot, is 28 feet in spread of main plane, and depth
of 6 feet in largest part. This would give a main surface of 168 square
feet, but as the ends of the plane are sharply tapered from the rear,
the actual surface is reduced to 150 square feet. Projecting from
the main frame is an elongated tail (shown in the illustration) which
carries the horizontal and vertical rudders. The former is made in three
sections. The center piece is 6 feet 1 inch in spread, and 2 feet 10
inches in depth, containing 17 square feet of surface. The end sections,
which are made movable for warping purposes, are each 2 feet 10 inches
square, the combined surface area in the entire horizontal rudder
being 33 square feet. The vertical rudder contains 4 1/2 square feet of
surface, making the entire supporting area 187 1/2 square feet.

From the outer end of the propeller shaft in front to the extreme rear
edge of the vertical rudder, the machine is 25 feet deep. Deducting
the 6-foot depth of the main plane leaves 19 feet as the length of the
rudder beam and rudders. The motor equipment consists of a 3-cylinder,
air-cooled engine of about 30 h. p. placed at the front end of the body
frame, and carrying on its crankshaft a two-bladed propeller 6 feet 8
inches in diameter. The engine speed is about 1,250 r. p. m. at which
the propeller develops a thrust of over 200 pounds.

The Bleriot XI complete weighs 484 pou