22 NOTES ON FLYING-MACHINES. 



is a sister model to C, hitherto it has been particularly unfortunate. 

 It is to be understood that in all places where metal is required 

 to join metal rigidly, soft solder forms the union ; and also that 

 all woodwork and lashings are glued, there are no nails or wood- 

 screws in any part of the machine. [The form of connecting rod 

 is now discarded for a composite structure made of two long eye- 

 bolts, stiffened against compression by a slip of pine lashed between 

 them ; the brasses are adjusted by nuts above and below.] 



A piece of wood about 2" x f " x J" will be seen in the end view, 

 this is not shewn in the longitudinal section or plan, it is glued 

 and lashed under the strut about the middle of its length, its use 

 is to keep the bands in a line with the strut and so prevent it 

 hogging ; in effect it shortens the length of the strut by half when 

 considering it as a hollow column under a crushing strain. 



The large machine on wheels (Figs. 1, 2, 3.) was made to ascertain 



1. The weight of a machine sufficiently strong to bear a man's 



weight and transmit his power. 



2. The most convenient form and arrangement of parts for the 



first named object. 



3. The area of wing that can be trochoided at about twenty 



revolutions per minute. 



4. The amount and distribution of the thrust. 



The weight of the machine and carriage is distributed thus : on 

 the caster 7 J lbs ; on each of the two hind wheels 5 lbs, = 10 lbs ; 

 total 17 J lbs. Weight of carriage 8 lbs ; weight of machine 

 alone 9^ lbs. The body plane has not been made, as its area 

 depends on the speed the machine and carriage can be driven, 

 but following the method of construction adopted for the wings 

 10 lbs. will amply cover its weight. The apparatus has sufficient 

 strength to bear a weight of about 170 lbs, turning the handle 20 

 times a minute, though many parts of it cannot have a higher 

 factor of safety than 2. It was thought that the best method of 

 applying the power was by turning a handle, as no simple means 

 of trochoiding the wings by a reciprocating motion, as in pulling a 

 pair of sculls, suggested itself. 



The caster is put on merely to show if inaccuracies in the 

 construction of the machine make it turn to one side. The main 

 vertical supports under the seat are hollow, with a light rod 

 inside sliding up through the ends of the seat; this is so 

 constructed that if the machine is propelled fast enough to lift 

 itself off the carriage, the light rods can be withdrawn from the 

 machine, and leave it quite free of the carriage. The forward 

 vertical supports have slides so that the machine can be tilted up 

 at any angle required. The three main beams of the carriage, 

 and the outer portion of the wing midribs are built of laths 

 one-eighth of an inch thick. The rigid connections between the 



