M. 



N. 



4' 11" 



4' 11 



3' 3f" 



3'0" 



371 



243 



144 



128 



3-58 



2-58 



5-625 



4-09 



1*57 



1-59 



- 41° 



-3° 



SOARING MACHINES. 211 



the type of the inscription that is plainly legible on the photo- 

 graphs but may be indistinct on the zincotypes : — 



Soaring Kites. 

 Length 

 Width 



Projected area of propeller, square inches 



„ ,, end surfaces ,, 



Total area, square feet 

 Weight, pounds 



Weight per square foot, pounds... 

 Angle of propeller 



Both kites have repeatedly soared in wind with a velocity of 

 ten to fifteen miles. 



M and N differ in several ways from the vulcanite soaring kite 

 described in the paper of June 1, 1898. The long tin tubes are 

 much stiffer and the propellers are made of redwood. M also has 

 a spring screwed to the front of its propeller so that a trial could 

 be made with the propeller rigid followed immediately by one 

 with the propeller springy. This showed the rigid propeller to 

 be the best. 



It is found that vulcanite immersed in boiling water and then 

 bent does not retain permanently the curve imparted to it • 

 neither does steamed wood unless nailed to numerous objectionable 

 ribs. Bent metal plate is worse than bent wood and weight for 

 weight is more flexible. There appeared no alternative but to 

 work the curve of the propeller out of solid wood ; this course 

 produces with some patience the desired article. When the best 

 curve has been decided on, curved wooden propellers will be pro- 

 duced by modern wood working machinery with as much facility 

 as any form of moulding used in architecture. 



A further consideration of the horizontal projection of a soaring 

 Third's win£ shows that the tip or flat part is approximately half 

 the area of the soaring part. 



When the wing is rigidly extended and the soaring part lifting 

 properly; the tip, when in the plane of the true wind, will have 



