796 The American Naturatst. [September, 
valued particularly plunged to the front in a violent blast of wind 
with force sufficient to tear out the rings. It rose into the air 
gradually higher and higher, until an elevation of at least 3,000 
feet was attained, when some part of the device giving away it 
lost equilibrium, and plunged through the air, striking the earth 
about two-and-a-half miles from the starting point, and 1000 feet 
higher than that locality. Another mile would have carried it 
tothe summit of the Flat Top Mountains. It was in the air 
about three hours, and I walked beneath it during its flight. Its 
course was directly against the highest wind I have experienced 
during my residence here. At times it did not progress, but 
went higher. It weighed one hundred and ten pounds, and had 
been well balanced for experimenting on surface manipulation. 
There was no lesson taught in this flight, the birds having been 
doing the same thing for a long time. It was an interesting 
spectacle to look at; so is a large bird in the same act. I presume 
Mr. Darwin’s provisional solution would apply to this plane as 
well as to the condors, but I am trying to explain the actual 
mechanical activity of both. 
The best effects produced were with a plane of 400 pounds 
weight and eighty square feet of surface. In a wind that would 
be rightly termed a gale, arising about midnight, this plane was 
thrown to about 7° from horizontal. It ran to the front against 
the rings at 10°, where the entire parallel component was neu- 
tralized, and at 7° it hugged the rings with a force that required 
a backward pull of fifteen pounds to detach it. ; 
This plane would make a splendid air navigator, and I would 
have no hesitation in trusting myself to it when steering, equi- 
librium, and alighting or stopping items had been worked out. 
I mean to say that it would navigate wind. Iam now just enter- 
ing on a course of experiments in calm air. 
The front ledge is an important factor in steadiness, but the 
rear curve I have entirely abandoned, surface manipulation being 
depended upon to produce the parallel thrust. My judgment is 
that I have succeeded in separating the mechanical devices of a 
bird’s wing which produce flight from those serving other life 
purposes of the animal. It has been an arduous task. At the 




