Evening star. [volume] (Washington, D.C.) 1854-1972, 1891-04-27

Flying or ballooning-which? lecture On
navigating the air was given last Friday night
in the regular course at the Tabernacle Church
by Prof. Hazen of the signal Office. After
acknowledging his indebtedness to an eminent
writer for the idea Of the title Of his lecture
the speaker said that he proposed to answer
the question, Neither! ''The great necessity
and importance Of some method Of air naviga-
ton may be easily seen when we consider that
1t has been proposed to spend $40. 000, 900.
simply as beginning, in terrifying our very
extended coast against an invading foreign foe.
Such Notifications. however. would be prac-
tically useless in the event of war for the
reason that foreign nations have already dis
covered the art of sailing through the air and,
In case of war. ships could easily approach out
OF range of our most powerful batteries and
mt out an air vessel which could snil far above
our shot and shell aud drop death-dealing dy-
Mantle in the center Of our largest city, thus
bringing us to terms at once. The only possi-
BILE thing to be done is to fight fire with fire.
1t seems remarkable fact that our people.
generally in the van of enterprises, are SO far
behind several European powers in inventing
practical air ship.
AT THE BOTTOM OF THE OCEAN OF AIR.
Another consideration is that our knowledge
OF the conditions lying at the bottom of our
storms can only be obtained by observing their
behavior at a height of 5000 feet or more At
present we are cropping about Mt the bottom OF
this immense ocean and are obtaining only a
very inadequate idea of the real forces at
work. Though thousands of ascents have been
made in this country and abroad, yet they
have lacked system and have been made mostly
for exhibition purposes, SO that they have
given only the most meager results There
have been great improvements in apparatus
and we are now well fitted for ,rscents in the
center OF rain, snow, hail, &c.
us 1t possible to 80 construct q machine that
we may ntilize the air the bird does? Prof.
Langley has recently said that this matter has
been left almost entirely in the hands OF char
latans. There have been, however. several
able and exhaustive studies Of the problem A
notable one may be found in an article on
Flight in the last edition Of the Encyclo-
p@dla Britannica by Mr.. Pettigrew. This writer
thinks that the principal cause of failure in
solving the problem has been in the use of in
flexible wings.
ARGUMENTS AGAINST FLYING MACHINES.
Prof. LIE Conte of San Francisco has made
an admirable summary of the arguments
against flying machines in recent number Of
Popular Science Monthly. LIST. tits impossible
to use the food which the bird uses to develop
power by any contrivance which can ever be
invented that will give one 1.-THE Of the effect
that the bird gets. That is to say, while posi-
u
using up an enormous amount OF energy in
very short time, might momentarily initiate a
bird, yet the motive power in such case would
be very rapidly used up.
sgd. 1t is impossible by the most delicate
mechanism and most perfect wings to equal the
perfection and adaptability of the bird in its
own element.
I'D. There is limit Of weight beyond which
it is impossible for bird to fly. 1t is probable
that the ostrich had the power Of fight in ages
gone by. but when its environment became such
that it did not need to use its wings to escape
from enemies, or when it began to grow larger
from any favoring circumstances. it used its
wings less and less SO that now 1t il entirely in
capable of flight 1t isprObable that the condor,
weighing fifty pounds and with spread Of wings
We may conclude then than We can never equal
a bird, and hence. that self-raising. self-sup-
porting and self-propelling flying machine
cannot possibly be built to carry man.
PROF. LANGLEY's EXPERIMENT..
"The greatest interest attaches to this subject
just now, from the fact that Prof. Langley, the
eminent scientist, has been performing some
experiments upon it and only this week has
presented an interesting paper before the Ma
tional Academy of Sciences in session in this
city. Prof. Langley illustrates his views by the
skater upon thin ice; if he stands still the ice
breaks under him, but if he moves rapidly he
il supported: in other words, by going fast he
prevents an accident. 1t is plain that by stand
ing still and waving his arms violently like the
wings OF bird he might put forth twenty times
the energy that he does in skating and yet not
save himself; this simply shows that he has not
proper appliances; but If he had a couple Of
boards or II rope by which he could support
part Of his weight the exertion required to
keep from breaking through would be much
less than in skating. This seems to be the key
to the whole situation, the man with perfect
appliances stands with ease upon thin ice
and i'll the same way the bird with its perfect
apparatus flies. This Is not all, however. Prof
Langley seems to have the idea that by passing
piane surface through the air the angle Of in
clination needed to keep it floating is much
greater with u slow velocity than with high
speed, but while the weight Of the plane is
greatly increased in the latter case the resist
ance of the air remains practically the same.
1t Is easy to see why this should be but We can
not infer that the bird is enabled to fiy by going
fast, for we know of many instances Of birds
soaring at very low speed for hours at time.
1t is well established that the soaring bird takes
advantage of a wind or current of air to ena-
BILE it to float almost motionless at times. Ex-
periments with card planes were tried to show
the extreme difficulty Of balancing and steer
ing plane surface in the air. 4 rapidly rotat-
ing plane could be sent a long distance, but it
was shown that such q rotation would be i'm
practicable in flying machine.
THE NEAREST SOLUTION.
''The probe m ofaerial navigation has reached
its nearest solution in employing gas holder
Of such shape as to present the least resistance
to directive agency and allowing this to sup
port all or nearly all the weight of the appara-
tus and passengers. Such continuance would
go with the wind, but by suitable propellers 1t
has been possible to defect the path of the
machine from the current or even to go at a
slow velocity almost against the wind"
Remarks were made showing that the mod