J 22 ON AERIAL NAVIGATION. 



the perfect ease with which some birds are suspended in 

 long horizontal flights, without one waft of their wings, en- 

 courages the idea, that a slight power only is necessary. 



Farther obser- As there are many other considerations relative to the 



"cations pro- ■ , . , „ . . , . ... , . 



mised. practical introduction or this machine, which would occupy 



too much space for any one number of your valuable Jour- 

 nal, I propose,, with your approbation, to furnish these in 

 Experiments your subsequent numbers ; taking this opportunity to ob- 

 ■m a tolerably serve ' that perfect steadiness, safety, and steerage, I have 

 terge scale. long since accomplished upon a considerable scale of mag- 

 nitude; and that I am engaged in making some farther ex- 

 periments upon a machine I constructed last summer, large 

 enough for aerial navigation, but which 1 have not had an 

 opportunity to try the effect of, excepting as to its proper 

 balance and security. It was very beautiful to see this no- 

 ble white bird sail majestically from the top of a hill to any 

 given point of the plane below it, according to the set of 

 its rudder, merely by its own weight, descending in un 

 angle of about 18 degrees with the horizon. The exertions 

 of an individual, with other avocations, are extremely in- 

 adequate to the progress, which this valuable subject re- 

 quires. Every man acquainted with experiments upon a 

 large scale well knows how leisurely fact follows theory, if 

 ever so well founded. I do therefore hope, that what I have 

 said, and have still to offer, will induce others to give their 

 attention to this subject; and that England may not be 

 backward in rivalling the continent in a more worthy contest 

 than that of arms. 

 Simple ma- As it may be an amusement to some of your readers to 



chme rising in machine rise in the air by mechanical means, I will 



the air by me- J . 



ebanical conclude my present communication by describing an in- 



»eans.} strument of this kind, which any one can construct at the 



expense of ten minutes labour. 



a and b, tig. 3, are two corks, into each of which are in- 

 serted four wing feathers from any bird, so as to be slightly 

 inclined like the sails of a windmill, but in opposite direc- 

 tions in each set. A round shaft is fixed in the cork c, 

 • hich ends in a sharp point. At the upper part of the cork 

 b is fixed a whalebone bow, having a bmali pivot hole' in 

 its centre, to receive the point of the shaft. The bow i& 



then 



