jleiial JVavigation. 19 



must be sufficient for a person to stand in, and move his hands freely. 

 All the circular hair lines between the spiral wire EFGH, and the hoop 

 efgh, represent small wires woven through the flattened shafts. On 

 these wires the balancing valves are to be hung, the same as in figure 

 1, only that the slips must be circular, of various sizes, and it will 

 require a number to make one whole circular valve ; part are restrain- 

 ed to EFGH, and part to efgh. W represents a circular balancing 

 valve, uv, its balance wire. Or these circular wires can be cross 

 wired and the valves similarly hung as those first described. ABCD 

 represent a large, strong, wooden ring or hoop whose circumference 

 or diameter must be somewhat less than the circumference or diameter 

 of the middle of all the flattened shafts, ac, bd, represent two strong 

 rods firmly fastened by their ends into the circumference of the hoop 

 or ring ABCD at right angles to each other. SS represent the car 

 which is to be strongly fastened to the rods a, c,b,d. 1, 2, 3, 4, 5, 

 6, 7, 8 represent standard braces, which are to be each about two 

 feet long : two standards make one brace, and there must be one brace 

 to every flattened shaft ; the upper ends of the standards of each 

 brace are to be firmly joined, while their lower ends should spread 

 about a foot. The upper end of each brace is to be moveably hung 

 by hinges or staples to the middle of each of the flattened shafts, 

 or that part of each shaft, where the weight and superficies are 

 nearest balanced. The other ends of the brace must likewise be 

 moveably fastened, by hinges or staples, to the ring or hoop ABCD, 

 when the braces are hung to the flattened shafts and the ring or hoop 

 ABCD : their lower ends ought to incline in, towards the car, so as 

 to make an angle of about forty degrees, with a vertical line or that 

 of gravity. The frame being constructed, wired and valved, the 

 aeronaut is to enter the car, stand upright and with his hands take 

 hold of any two opposite sides of the hoop efgh, and raise it up and 

 down, when it will give the wing or wings the intended motion- I 

 shall now illustrate the balancing principle of motion. 



In figure 1, as all the weight is to be suspended from the axles 

 EE, ee, and all the valves are hung on the underside of the wings, 

 so as to open about forty degrees downwards, when the aeronaut 

 raises the handles K, k, quickly up, all the valves between the axles 

 EE, ee, open and let the incumbent air through, while those beyond 

 close air tight, and strike the air proportionally to the quickness of 

 the motion. When he brings the handles down quickly, all the valves 

 between the axles EE, ee, close, air tight, and strike the air similarly, 



