San Antonio daily light. [volume] (San Antonio, Tex.) 1886-1907, 1891-10-12
AERIAL NAVIGATION.
Some Reasons Why it Will BE Eek
tremly Difficult 70 Travel
in the Air.
New York RAILROAD Gazette.

Prot. Langley, in his memoir on
serodynamics, has indicated the
vet inchoate air OF constructing suit
aole mechanism for guiding heavy
bodies through the air on certain
principles which are eDunciated
therein, In glancing back over the
narrow field wherein efforts have
been made by man to fly we see that
leaving ont few abortive attempts to
make bird OF him self by fastening on
sIngs, his various contrivances for
traversing the air have been based
upon the principal of buoyancy az
exemplefied in The balloon. The bal
loon itself, fitted only for rising and
falling, aud incapable of horizontal
| movement excepting by the action OF
uncomfortable air current, does not,
strictly speaking, come within the
| category, one, outside of q very limi.
| ted employment for observation pur-
poses, il worthless. To supply it's
deficiencies, and make OF it a selfpro-
polling AID dirigible vehicle, has
usually been the aim of the air-ship
builder in fancy and in fact. The
forms suggested have been mu tifar-
Gus in detail but alike in the general
feature os supporting the vessel and
it's load by the lavity of gas, or of q
vocuum, confined In a receptacle OF
SUFFICIENT displacement. All such
actual efforts have invariably failed
of satisfactory results and practically
speaking, must fall of useful accom-
plishment with any form of propel-
ling engine or known rouce of power
because OF, leaving out other grave
mechanical difficulties, the enormous
ly disproporti lnate selatiOne between
the supporting and the supported
part of the apparatus. A successful
commercial machine ofthis sort must
necessarily possess the power within
itself to advance in the teeth
winds at rate greater than
their velOcitles, and as the motor at
such times must work upon the rece.
ding air the reserve and the waste of
power must be enormous. Each in
crement of weight to engine or fuel
involves q corresponding increase OF
displacement in the supporting part
and a sill greater ratio of increase in
it's resistance, and the condition Of
reduction and absurdum are''sOOn reach
ed. Attempts TO overcome these re-
strictlons have been numerous and
futile. whether directed to the shape
of the supporting part or to the adop-
tiOns of new forms and applications
of power and although unques Iona bic
god and honest effort has sometimes
oeen eXpe,, ded in this line of expert
ment, 1t has neverthele-s come to pass
chat the man with a flying machine
10 in great danger of being cOntC unded
with the inven tors of perpe tual mo-
lions or transcenientai motors. 1t is
therefore rot to be Wondered at, and
is in reality quite necessary, that
Prof. Langley should lay much stress
nuOn the ESSENTIAL and important
difference between experiments in fly
ing and experimental demonstrations
of certain propositions in aerOdyua-
mics which prove that such flight
under proper direction Is practicable
This being understood, he goes on 10
saw, " may say that these research.
as have laid to the result that mechau
cal sustentation of heavy bodies in
he air. combined with very great
speeds is not only possible, but with
ia the reach of the mechanical means
we actually po, sess, and while they
are nov aS hdNS SdlI W We
ronstrate the art of guiding such
heavy bodies in flight, they do show
chat we have now the power to sus-
tain and propel them. The expert
ruents which are described and re-
cord ed and tabulated in the memoir
with great mInateness and deliGacy
we're generally speaking made with
the one spec fic object calculating he
dynamic principles lying at the basis
of the aerial mechanical flight OF
bodies denser than the air in which
hey move, they were extended also,
to The relation of propeller wheels
use on some Of the trials, and 10
measurements of power eXerted and
returned; and they were in no way
concerned with aeronautics or the
use of balloons or objects lighter than
the air Other than the propeller
wheels just referred to and which, of
course nave only secOn Diary relation
the objects experimental with were
thin vanes of wood sly led planes by
Prof. Langley their surfaces being
planes. These were of various di-
menslons, a representative size being
| foot square and one eighth of an inch
hick; when necessary they were
stiffened by strips OF metal. Tho pur-
pose of the Investigations required
~ that the planes should be caused
10 move through the air if in flight,
and at various inciinations ana
speeds; (2) that during such move
ments the resultant air pressures
upon the planes. the position of heir
centers and their vertical and hori-
ION tai components should be accurat-
lv determined in each case; sc that
the relative times OF falling vertical
ly through given space consumed
by planes dropped wuen moving at
aiHarent known horizontal Valncitias