r>50 



THK (lUKATEST FLYTNG rREATUKK. 



Now we wish for our especiul purpose of conipariuj^' tliis bird with 

 other flyiiiji" things, to know (a) the sup})orting" urea in squai'e feet, (/>) 

 the weight, and {<■) the power for (1) a tiyiiig machine of man's inven- 

 tion, whi(^h has actually flown for compai'ativeiy long- distanees, (2) 

 like facts for this the largest of nature's flying machines, and (8) for 

 some of our present birds. To recapitulate, we need for our special 

 purpose at least the following data for any flying thing, namely, (1) the 

 supporting area in square feet. (2) the weight in pounds, and {?>) the 

 horsepower which drives it through the air. 



It is evidently impossible to exactl}^ recovei- all of these for the 

 Pterodactyl, and hard to definitely esta])lish all three even in living- 

 specimens, but we may assume in the case of the horsepower that it is 

 proportioned to the area of the attachment of the muscles which moved 



Diagram of the Aerodrome. 



the bird in flight, an assumption which is doubtless only approximately 

 true, but may serve our immediate purpose. With this understand- 

 ing 1 present, together with an instantaneous photograph of a steel 

 flying machine in actual flight (PI. 11) (repeated here from a previous 

 publication), a diagram (Pis. Ill, IV) representing the above three 

 facts in the case of (1) the flying- machine, (2) the Pterodactyl (Ornitho- 

 .stoma), (3) the condor, and (4) the buzzard, all soaring things, and (a) 

 the wild goose, (6) the pigeon, and (7) the humming- bird, which last 

 three fly by moving their wings. 



This steel flying machine shown in the instantaneous photograph 

 had a supporting area of 54 square feet, a weight of 30 pounds, devel- 

 oped 1^ horsepower, and repeatedly flew from one-half a mile to 

 three-(iua"ters of a mile. These facts are represented in the diagram 

 by the three rectangular figures whose areas are proportional to these 

 values. Immediately after it comes nature's greatest flying machine. 



