New-York tribune., 1908-06-02
AEROPLANE MODELS.

In such self-propeied airshps as secure buoy
apcy by means of gas there Is notable UNIFORM
ity in outward appearance. Some are lafser
than others and some are more slender than
others but they all have reservoirs Whlch are
virtually cylindrical in shape and which are
pointed at both ends. In design they resemble
each other closely and differ little from the
pattern set by Messrs Iissandier. Krebs and
Renaud a quarter Of century ago.
Greater diversity is to be observed in the
forms of the craft which remain aloft only while
they are moving forward. The wright Droth-
ers and Delagrange, who at present nave spe
ciai claim on public attention, follow precedent
established by Lientha i'll the last or his GID
ing experiments. They employ two sheets or
CLOTH stretched horizontally one above the other
and having greater extent sideways than from
front to rear. One of their machines looks
good deal like single section of colossal box
kite In that invention which originated with
an Australian (Hargrave), there are two sec
tions or cells one ahead of the other Far
man. Rierot and possibly other devotees Of the
aeroplane use two cells, thus having at their
disposal four lifting surfaces instead OF two
Langley, on the other hand, managed with con-
siderable success) with one gap in the mid
die divided his airship Tito what suggested a
pair of wings, but the wings were arranged IN
the same plane. Santos Dumcnt Is said to have
modelled an seroplane after butterfly, and
this would have borne some resemblance to the
Washington experts "aerodr0me,' no doubt,
though It does not appear to have had thor
ough trial. For some reason or other the young
Brazilian abandoned his experiments with this
type of machine about two years ago. His first
design, however, is known to have been rather
complicated. and was not to- be classified with
anv of those here mentioned
When tests with aeroplanes have been con-
y, tod for nrt tNyO M ChOlld
sbe TO determine whether one style is distinctly
superior to the Others and, If so. which is the
best On general principles simplicity Of form
and construction is greatly to be desired, but
il should not be sought at sacrifice of stability.
If as is not unlikely the aerOplane can be cap
sized more easily by gust Of wind than can
dirigible balloon steadineSs during flight is
more essential in the former than In the latter.
Professor Graham Bell bc.:5ves that his tetra-
bedral kite composed of scores Of cells, has
greater lifting capacity and displays greater sta
biIity than the ordinary aeroplane. Hence In
the final comparison of heavier than air" ma
chimes with another this device should be
included, elaborate as It's construction is.
The differences among the best known
planes to-day are by no means limited to their
lifting surfaces. In getting under way it is
usually necessary for one Of these machines TO
run along the ground for distance Of several
rods. Ascent is effected very SLOWLY. Al the
outset friction with the ground must be over
come Some inventors for this purpose put
wheels like those of bicycle underneath the
machine. Others rely sliding device. 1t
has been proposed to get around the difficulty
encountered In launching an aeroplane by equip,
ping it with screw revolving In a horizontal
plane and powerful enough to- raise the burden.
Whether in actual practice the drawbacks to
that method would not more than offset its adj
vantages Is question yet 10 be solved. Before
the ideal aeroplane Is developed still another
plan may be suggested. In the means employed
TO preserve equilibrium there is also enough
riety 10 make the ultimate choice seem doubtful
at present. Evidently much more play must be
given TO inventive talent before the merits of
the acropiane can be correctly estimated, but
the. progress already made deservedly com
niands ii large measure Of popular interest