their combined exertions.

All applications to be made to D. E. Colombine, Esquire, 8 Carlton
Chambers, Regent Street.

The applications did not materialise, as was only to be expected in view
of the vagueness of the proposals. Colombine did some advertising, and
Mr Roebuck expressed himself as unwilling to proceed further in the
venture. Henson experimented with models to a certain extent, while
Stringfellow looked for funds for the construction of a full-sized
monoplane. In November of 1843 he suggested that he and Henson should
construct a large model out of their own funds. On Henson's suggestion
Colombine and Marriott were bought out as regards the original patent,
and Stringfellow and Henson entered into an agreement and set to work.

Their work is briefly described in a little pamphlet by F. J.
Stringfellow, entitled A few Remarks on what has been done with
screw-propelled Aero-plane Machines from 1809 to 1892. The author writes
with regard to the work that his father and Henson undertook:--

'They commenced the construction of a small model operated by a spring,
and laid down the larger model 20 ft. from tip to tip of planes, 3 1/2
ft. wide, giving 70 ft. of sustaining surface, about 10 more in the
tail. The making of this model required great consideration; various
supports for the wings were tried, so as to combine lightness with
firmness, strength and rigidity.

'The planes were staid from three sets of fish-shaped masts, and rigged
square and firm by flat steel rigging. The engine and boiler were put in
the car to drive two screw-propellers, right and left-handed, 3 ft. in
diameter, with four blades each, occupying three-quarters of the area
of the circumference, set at an angle of 60 degrees. A considerable time
was spent in perfecting the motive power. Compressed air was tried and
abandoned. Tappets, cams, and eccentrics were all tried, to work the
slide valve, to obtain the best results. The piston rod of engine passed
through both ends of the cylinder, and with long connecting rods worked
direct on the crank of the propellers. From memorandum of experiments
still preserved the following is a copy of one: June, 27th, 1845, water
50 ozs., spirit 10 ozs., lamp lit 8.45, gauge moves 8.46, engine started
8.48 (100 lb. pressure), engine stopped 8.57, worked 9 minutes, 2,288
revolutions, average 254 per minute. No priming, 40 ozs. water consumed,
propulsion (thrust of propellers), 5 lbs. 4 1/2 ozs. at comme