475 
1879 •] Artificial Flight . 
Is there any need for me to dwell upon this negation of 
all hope for those who desire to navigate, and not to float 
and stagger about, in the air ? 
There remain, therefore, the advocates of the screw-pro- 
pelled plane. For the le(5ture-room this is a very pretty and 
effective experiment, and I have propelled such for years 
with screws both fore and aft ; but I have failed to see safety 
to life under such a surface, even were there not another 
objection, and that a fatal one, to their use. 
I have always said that any aerial machine, to be safe, 
should have sufficient power to rise from the ground. It 
will then possess power to control its descent. But no plane 
has hitherto been devised capable of rising from the ground 
with any preliminary run which could be imparted to it. I 
have watched such experiments with much interest. Mr. 
Linfield’s ambitious attempt failed to afford any indication 
of rising power, although he has travelled upon wheels at 
somewhere about 20 miles an hour, with a surface overhead of 
about 300 square feet set at an angle originally. The dimen- 
sions are — Length 40 feet, width 18 feet, height 15 feet. 
The weight of all, including Mr. Linfield, is 304 lbs. 
Mr. Moy also tried with a model weighing ij lbs., also 
upon wheels, the screws actuated by twisted india-rubber, 
but he failed in my presence to effedt any rise at all. He 
succeeded in attaining only 10 miles an hour. 
The preliminary run with the velocity requisite for success 
seems to me to be fatal to any attempt of this nature — 
equally so any descent from an elevation— to attain the 
initial velocity. 
The bird with extended wings does not rise by passively 
holding out his wings as a plane, but during his preliminary 
run he either slowly waves his wings or else tremulously 
vibrates them, which enables him to feel the air, and gra- 
dually to obtain a fulcrum upon it. 
There is yet another group of inventors who hope, by pre- 
senting a suitable supporting surface to an accommodating 
breeze, to be lifted thereby, and then, by the aid of gravity 
and this friendly breeze, to sustain themselves like a kite, 
and even to progress when they get accustomed to the 
position. 
For the last three years I have myself been a continuous 
experimenter, and one can scarcely work in any field of 
science without advancing a step in knowledge. Much more 
likely is the investigator to be rewarded if the field has been 
almost abandoned. Many a nugget has been dug out of a 
deserted claim. I will remark, however, in passing, that 
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