3«3 
1880.] Flighty Aspirations. 
velocity. For instance, a sheet of stiff cardboard can be 
propelled horizontally by means of a finder loosely placed at 
the rear edge. By increasing the velocity beyond the neces- 
sary requirement the cardboard, or any plane surface, will 
depart from the horizontal in an upward direction, in obe- 
dience to the increased resistance of the air, and the rate of 
velocity being increased it will turn over towards the hand. 
It is the desire of some workers to obtain support in the 
air by extending the area of such surface and propelling by 
screws : upon a small scale this has been proved practicable. 
Models of dimensions and weight capable of being launched 
from the hand are very effective ; but when those of a larger 
size, which cannot be thus manipulated, are attempted to 
be put to practical use, a preliminary run upon the ground is 
necessary, and hitherto the velocity under those conditions 
being retarded by friction, although upon wheels — has not 
been attainable. This velocity is an absolute condition, so 
as to enable the apparatus to meet with that atmospheric 
resistance which would force it to leave the ground and con- 
tinue its flight in the air. Certainly no rails have yet been 
laid down with the objeCt of reducing friction, but the aid of 
an incline has been enlisted without effeCt. No experiment 
worthy of the objeCt sought to be attained has yet been 
attempted by any one holding the opinion that eventual 
success lies in this dire<5tion. 
My idea of a satisfactory trial would be the employment 
of great power, large and strong surface, and as fri(5tionless 
a road as could be devised ; for instance, upon a straight 
line of rail. 
The interest which is attached to many scientific subjects 
is, however, absent in this, so far as respedts the public and 
amongst scientific men generally. So little understood are 
the principles upon which the hope of flight is founded that 
it is well known that if a discussion is started in any scien- 
tific periodical there are scarcely any instructed minds to 
follow it up, and the subject dies away almost from its birth, 
eliciting nothing but worn-out ideas, and always drawing out 
the suggestion that gas should be used to take off the dead 
weight. This suggestion is as absurd as the converse one 
of using an aerial machine to propel a balloon. 
Those who saw poor De Groof when he left Cremorne 
Gardens, in the hour of his death, dangling from the balloon 
in his comparatively fragile framework, will call to mind the 
diminutive appearance of the apparatus compared with the 
bulk of the balloon. To take off the dead weight would 
require as large a balloon as usual, but still of such a 
VOL. II. (THIRD SERIES.) 2 E 
