New-York tribune., 1902-10-11
AERONAETTCS.
A USEFUL SURVEY OF THE SUBJECT.


TRAVELS ~ SPACE History Of Aerial Navi-
sauon i5y =. Seton Valentine and +. J. Tom
Hurst q Blackett '''' 'l'
The marked development Of interest in aero
hauucs IN the last ten years, the fact that en-
sineers and scientists Of worldwide reputation
nave recently investigated the subject. and the
soantiness OF available literature combine 10
create demand for a work like or better than,
this The book has its faults The arrangement
or the matter is almost strictly chronological.
There is no attempt 10 show the evolution Of
the different types Of airship separately. Amerl-
cans VIII wonder why John Wises wonderful
voyage nearly thousand miles in length,
nan a century ago. is referred 10 SO briefly All
the same the story is apparently accurate as far
as IL goes. While not entering into technical
ties so extensively as Chanute did in Progress
IN frying Machines" ten years ago, Messrs. Val
entine and Tomlinson up 10 date. That con-
sloerauon Is one OF great Importance, i'm view
OF recent activity in aerial navigation. The book
is handsomely illustrated. too. Finally, II has a
short introduction by Sir Hiram Maxim. one OF
the highest living authorities in this branch Of
experiment
Naturally, the form and motion II a bird have
given many suggestions TO inventors The rude
sketches Of a flying machine in Da Nincis note
possibility Of utilizing the principle of wings.
one of the first persons TO do so with even linz
tied success was Allard. who in lG'io made a
number Of short flights. Two centuries more
elapsed. during which many others attempted 10
navigate the air 10y the same means without ac-
complishing much. before lie Bris appeared This
Frenchman, a mariner 10y profession. had closely
observed the albatross while voyaEiuE around
Cape Horn and the Cape Of Good Hope. and i'm
lN'Aa built a machine that was modelled that
remarkable bird. With this contrivance ne not
only ascended 10 height Of three hundred feet,
but he kept himself aloft for several minutes.
Propulsion with wings. however is now re-
garded as too difficult an undertaking Whatever
may be the secret Of a birds power. no reputable
engineer to-day believes that wings promise
anything except support. Progrcss in a hori-
zontal direction must be effected by other
agencies.
Montgolher and his first imitators sought
merely TO ascend and 10 drift. But early in the
nineteenth century aeronauts began 10 consider
the feasibility Of directing a balloons course.
LennoN, in 1854. built ca that was long and
narrow. like a ship, and which was meant 20 be
sustained 10y a gas bag. He provided il with
rudder II was too cumbrous however. 10 rise.
The first triumph with a self-propelled gas bag
was achieved by Clifford in 49,. His machine
ships. Clifford used steam to actuate his screws.
Renard employed electricity. and adopted san
toss gasoene engine. But they all relied upon
huge silk receptacle containing hydrogen 10 keep
them aloft. Won Zeppelin, Severe. Spencer
Stevens and Barton have all followed the last
mentioned plan, though in certain details of con-
struction their craft have differed more or less
from the Santos model.
one Of the first inventors 10 discard the prin-
ciple Of a balloon altogether and 10 rely on a
Nat, horizontal surface alone for support
Henson. He emphasized the fact that a card.
thrown edgewise and in a slightly inclined posi-
ton, would rise long the propeller force
lasted. 1Ie designed an aeroplane in 1872 which
theoretically practicable. but did not actu-
ally ny. He did not call into play. as LandeIle
proposed TO in 1865, Of lifting screws on top
of HIS craft. for temporary service. Liienthal,
between 1898 and 1896, gave wonderful demon
strations OF the support 10 be derived from q
pair Of Outstretched and stationary wings. when
progressive motion was once secured by jump
ing of a housetop a cliff. Then came Maxims
and LanEley's ventures with the aeroplane. I'm
1924 and 1896. These have never been followed
up, they ought 10 be. but such disinterested
and highly competent judge as Lord Kelvin be
Ieves that the greatest practical success in
aerial navigation viii be effected with this type
OF machine.
In the Introduction 20 Messrs Valentine and
Tomlinson's history, Sir Hiram Maxim points
out the insupera ble difficulty which is encoun-
tered in navigating with such craft as that ~
Santos. 1t is not possible he says. TO make
a balloon strong enough 10 be driven through
The air Al any considerable speed and az the
same time light enough 20 rise. Therefore bal
looms must always be at the mercy of "A wind
no greater than that which prevails al least
three hundred DAYS in the year. In an
nature We do not md a single balloon. All
natures flying machines are heavier than the
air. and depend altogether on the development
Of dynamic energy. In natures machines the
amount Of energy developed for given weight
Is very great indeed. but no greater than the
artificial motors which are able 10 produce
at the present time"