Wiyeng. 
470 
aman, as being not naturally designed to such a mo- 
—y~" tion. It were, therefore, worth the enquiry, to consider 
whether this might not be more probably effected by 
the laboor of the feet, which are naturally more strong 
and indefatigable. In which contrivance the wings 
should come down from the shoulders on each side, as 
in the other; but the — — them should be = 
the being thrust out an wn in again, one after 
poy so as each leg should move both wings, by 
which means a man should as it were walk or climb up 
into the air.” In all ae —_ s, however, the idea 
of Ayi exertin ani ers alone on wi 
has _ Suntenatl ; though Che utunost euuiibdiice ef 
its success continues still to be entertained, and, as we 
shall immediately see, it has actually been put in prac- 
tice. The close imitation of nature, also, under the mo- 
dification required by the difference of materials, is in- 
variably to be preserved. : 
Among the most recent authors on this subject, may 
be named Sir Cayley, who endeavours to 
shew that there is nothing adverse to the soundest 
reasoning in ing to overcome thedifficulties which 
men experience in elevating themselves in the air. 
He shews that flight is purely mechanical, for by a sim- 
ple experiment in disposin fo 
angles to each end of a sed, and presenting an oblique 
surface to the air, this apparatus will of itself rise, when 
a rotatory motion is produced by the relaxation of a 
ing untwining a cord connected with it, and encir- 
ching the rod “« The flight of a strong man by great 
muscular strength,” he o , “ though a curious 
and creme? J circumstance, in as much as it will pro- 
bably be the first means of ascertaining this power, and 
supplying the basis whereon to improve it, would be of 
little use. I feel perfectly confident, However, thet thisno- 
ble art will soon be brought home to man’s general con- 
venience; and that we shall be able to transport our- 
selves and families, and their and chattels, more 
securely by air than by water, and with a velocity of 
from 20 to 100 miles per hour.” Bishop Wilkins, in- 
deed, was long ago so confident of success, that he an- 
tici the period when a person should as readily call 
for his wings to make weeny, as he then did for his 
boots and his horse. Sir George Cayley continues : 
“ To produce this effect, it is only necessary to have a 
first mover, which will more power in a given 
time, in Sha re to its weight, than the ani 8- 
tem of mu ” He seems to infer, that he has made 
experiments on a considerable scale; but we are not 
acquainted with their nature or result ; and we are pre- 
cluded from discussing his theories, by the necessity of 
referring to what seems moré decidedly practical. 
Just about the same time, Mr Walker of Hull, whose 
sentiments we have already quoted, directly proposes a 
machine whereby flying shall be accomplished ; and he 
maintains that he is the first person who has discovered 
the real theory of the flight of birds. “On corisidering 
the ae pers wee - ae that by means of 
a pair of wings a tail duly expanded in a ectly 
passive state, and aloft in the air, without any Peni 
metion, a bird procures a suspendin, wer, which 
counteracts the specific gravity of its , and pre- 
vents its being precipitated to the stone. But this 
is assuming too much ; for it is , that 
‘ ent mitment a oy of the win, 
in tly suspended motionless in the air, 
they would fal tothe earth without it. With respect 
to quill-feathers, which are here the prime : 
he observes, that, as they were intended to swim in a 
Suid so light and subtile as the air, it was necessary 
ur quill-feathers at right - 
u 
" ascen: 
‘tally e 
feet long, 
ee ee iad rete, what bated 
agents, ‘mit the passage 
FLYING. 
they should consist of the lightest materials imagina« 
ble. that being intended Pret upon the air with 
Srould poser tau ‘etrcngth wich lastly: oT 
should possess mu w 
was expedient, too, that the quill-feathers 
and open, to let the upper air pass through 
to facilitate their ascent when 
wards. It Mage _ that 
close together, formin, wing into a complete sur- 
face of ab, when they are by the rouscular power 
the bird forced down, in order to give a more 
hold upon the air below, and by their means 
bird up, Now, if we do but examine the quill-feathers, _ 
we shall as ay beng apgecro | 
elasticity, and vi ittle ific 
webs = broadet ‘oh one side the ak 
other, which causes them to o 
up, and to mgt as they come 2 
the pu ave ly i 
poh er ba ee gener 
tive state, it appears that flight is attained from the 
sistance of the air or percussion. ‘ When a bird, 
the power of its pectoral and deltoid 
into action, and strikes them 
periecty vertical direction upon the air below, that air, 
dws in 8 
re- 
pressed by the stroke, makes a resistance by 
Ine 
its elastic power against the under side of the 
ion to the rapidi 
of the stroke and the ¢ 7 
sions of the wings, and forces the bird upwards: at the © 
same time, the back edges of the wings 
weak and elastic than the fore edges, they 
the resisting power of the com air 
upwards 4 at: the same sak aaee acting 
them with its elastic power, and 
being 
edges, 
thereby causes 
jectile force which impels the bird forward. 
we see that by one act of the wi 
both buoyancy and S i t 
ced upwards, and the wings are in action, 
a and forced downwards, it consequen' 
scends. But the most im’ t use of the tail 
more — 
rushes 
; 
mn. "When the tail fs for : 
bird 
de- 
is to” 
support the posterior bh i of the bird, and to prevent : 
the vacillation of the whole. 
Fortified by these principles, Mr 
an a 
flying shall be attained ; and this is to consist of a case 
Walker proposes 
whereby, from the action of wings, © 
formed of light materials, provided with wings of the ~ 
requisite dimensions, to be put in action by a man sit- — 
ting, and as if rowing a The wings are recom- 
mended to be each about eight feet long when 
ded ; and fastened upon the top edge « 
car, with twa joints each, so as to admit a vertical 
ties saa al iatlied as aii SS ae 
man sitting and working an upright lever in 
of the car. A tail of seven or eight 
f 
z 
FB 
Fe 
to the 
der of the car, and spread out flat 
inthe same manner as we see the tail of 
siderable “ie Be porghn id to the structure of 
wings an , @ point never escaped 
torsthis thie euler; and Mr Walker p that 
ee doe: vids consist of six slips 
e, , und tapering to a point ; wra 
ee gin eee 
twine, an with cork along : : 
‘next to be covered with silk very compactly w 
and as impervious to the air as possible. This 
aie Ge fo SSpaesie CS ema 
of the air as ‘the wings move w 
come down, 
-feathers in 
‘i 
7 an we ny 
fn 
ae 
a = 
a 
s 
& 
i 
7 
s 
‘close together again as 
the same manner as the 
Es 
é 
a5 
BF 
> 
E 
; 
