Evening star., 1932-01-05

FLYING Machines" in 1882, DR.. Zahm can
now look back on so years of continuous
activity in this field At the time when
aerial navigation was considered the
business of fools and dreamerS, DR..
Zahm frankly declared his firm belief
in the possibility of human flight. This
was several years before Octave Cha
mute, Samuel Picrpont Langley or
Hiram Maxim began their experiments
the Wright brothers we're only boys and
Glenn H. Curtiss hardly more than a
baby.
Albert Francis Zahm was born in
Lexington, Ohio, January 5, 1862. He
studied at Notre Dame University, where
he graduated in the classical course at
the head of the class of 1888, and took
the masters degree two years later
Becoming deeply interested in the sub
ject of aeronautics, he devoted himself
to the study of that subject and its
allied branches, especially shop work
physics and applied mathematics, which
he taught at the college.
While teaching at Notre Dame he
acquired, through his older brother,
Rev. j. A. Zahm, author and scientist
a good working library on aeronautics
from Europe. He made numerous ex-
periments with models and conducted
Investigations Of wind currents, and oc-
casionally contributed papers on aero
nautical subjects to the college publica-
tionS. There existed at the time two
schools of enthusiasts, who, in DR..
ZahmS words. with more acrimony
than love, have waged phophetic con-
tention over the future illimitable sky"
They were the aeronautS and the avia-
tors, the former having at least been
able to quit the earth, the latter point
ing to the birds as an apology for their
own existence" DR.. Zahm was an i'm
partial advocate of both heavierthan-
air and lighter -than-air craft, and he
has made valuable contributions to
both. 1t is interesting to note, now,
when motorless fight is firmly estab-
lished, pursued as sport, that one of
its first and NOSE persistent advocates
was DR.. zahm. One of his first aero
nautical papers was on soaring and
one of his latest, published in 1880. was
on the same subject.
For the purpose of bringing to light
what had been done in aeronauticS and
to facilitate cooperation between the
various experimenterS and enthusiasts,
he inaugurated the International Con-
ference on Aerial Navigation in con-
nection with the World Fair in Chi
cago in 1898. The conference was one
Of the memorable events in aeronautical
history in America, and its published
proceedings furnish a broad survey of
the status Of aeronautical science at the
time.
DR.. Zahm read two papers of his own
at the conference. The first, "Atmos-
pheric Gusts and Their Relation to
Flight" was a contribution to an ex-
planation of the problems of soaring
flight from the pulsations of the wind. !
The paper shows DR.. ZahmS character
iStic inSistence on exact measurements,
as opposed to the approximations and
gueSswork employed by unscientific en-
thusiaStS and sometimes even by scien-
fists. 1t also shows his unusual inVen-
tive genius in devising apparatus for
obtaining such measurements. On these
two counts DR.. Zahm is not surpassed
or even equaled by any one among the
pioneers.
The second paper was Stability of
Aeroplanes and Flying Machines" the
result of numerous experiments with a
great variety of models 1t contains
complete description of a three-torque
control system for airplanes, including
torsional wings.
But the inventors Of the day were
not interested in manually operated
apparatus for preserving lateral stabll-
ity. They were trying to build auto
matically stable flying machines. AL
most 10 years later the Wrights saw the
necessity for such third rudder and
invented their wing warped device on
the same principle.
From 1893 to 1895 zahm studied
physics at Johns Hopkins University
and then came to Washington as asso-
ciate professor at the Catholic UniVer-
sity. Here he conducted series Of eX-
perimentS to determine the air re-
sistance of projectiles. The apparatus
used was entirely novel and ingenious,
invented by himself. Most remarkable
was a new chronograph, capable OF
measuring accurately intervals in time
down to one-millionth Of second. or
about 100 times more accurately than
was possible before.
DR.. Zahm had long wished for an
opportunity to undertake extensive
aeronautical research with adequate
equipment. and in the Spring of 1901
the opportunity came through Mr..
Hugo Mattullath, inventor and business
man Mattullath had designed NAM
moth airplane, but before going into
actual construction his financial back
erS desired to test the SoundneSS of the
design. DR.. Zahm offered to conduct
the tests, expecting in that way to learn
much of value to aeronautical science
in general Mattullath provided the
funds, and under DR.. Zahm's direction
a special laboratory was erected on the
grounds of the Catholic University.
There are two general methods of
measuring air resistance; either to pro-
pei the body against the air or the air
against the body. The second method
was chosen, and wind tunnel built, so
feet long and feet square. Wind tun-
nelS Of a kind had been constructed in
Europe before. but they were small and
primitive The Wright brothers also
later in the same year, constructed
small wind tunnel which, in spite of its
crudeneSs, was of great help to them
DR.. Zahm's tunnel, however, differed
from the others. not only in size, but
by being adapted for the most accurate
measurements. The most exacting pre-
cautions were taken to eliminate all
sources Of error. Many new and deli
cate instruments were invented by Dr.
zahm, among them a pressure gauge
graduated to millionthS Of an atmos-
phere. The laboratory was nothing less
than the first full-f1edged aeronautical
laboratory in the world.
One of the chief objects Of research
in the wind tunnel was the friction Of
the ah This had been considered neg
ligible by all previous investigators. DR..
zahm now proved that skin friction.
far from being negligible, is about half
of the total resistance. When his now
classical paper, Atmospheric Friction,
With Special Reference to Aeronau-
tics" in 1904 was presented to various
learned societies, and to the aeronau-
tical conference in st. Louis it came as
revelation, and Chanute called it little
short of revolutionary" Physicists had
hitherto confused two entirely different
things, head resistance and skin fric-
ton, and treated them as one. They