New-York tribune., 1919-05-04

SbO4 NOAO4tlOIS are IlOES pLSf
in winter, and the net result is about
in the two seasons. Moreover, the
greater fog percentage in summer just
about offsets the greater percentage
OF cloudiness in winter, Fog is disad-
vantage chiefly because of its inter-
ference in making observations with
drift indicators. The Newfoundland
fogs in general are Of small vertical
extent and do not extend far inland.
They should not prove a hindrance to
landing if the landing field is located
some distance from the coast"
Near the Irish coast the percentage
Of Of days on which fog. occurs varies
pert cent in winter, in contrast to the
Newfoundland average Of so per cent
in summer and 20 to 35 per cent in
winter. Fogs rarely occur near the
Azores or between them and Portugal.
The statements made by the mete-
biologists in relation to airplanes ap-
ply equally we'll to arships, they say.
Airships, however, because of their
greater capacity for fuel and their
independence of motor power to sus-
tain them, are capable Of remaining
in the air relatively long time and
are not so vitally depedent upon favor
dDiS WluQ COuUlLlOuS.
Compasses Are Deceptive
Compasses hava been found to lose
much of their precision on airplanes,
and on transatlantic flights it is
believed they would be somewhere near
useless. The oscillation of the plane
itself is deterrent factor, and others
are the attraction of the motor or
machine material for the needle, and
1nT.u fSpc h
tons while making flights at high
speeds. Under clear skies sextant
observations make possible the correct
determination of position, but in
cloudy weather the compass is the only
guide unless the aviator can fly high
enough to get above the clouds.
1t is believed necessary that trans
airplanes, in the present stage
of development, should be in constant
touch with ships that could indicate
positions by wireless. Developments
in wireless have made it possible to
tell the direction from which an air
message is sent
The difficulty of accurate flight
would be greater if the airplane were
aiming at comparatively small group
or Ireland or the coast Of Europe.
Professor Marvin points out that it
would be possible for an aviator, fly
ing over the uniform surface of the
ocean, to turn his machine uncon-
sclousiy and fly away from his object.
Also, II his machine, making a hypo-
thetical speed of 80 miles an hour,
should run into head wind of 90
miles an hour, he might stay indef-
nitely in the same position over the
ocean. On land an aviator can tell
whether wind is aiding or retarding
him, but over the changeless sea, un-
less there we're ships within the
vision, he would have little or nothing
by which to gauge his progress.
All Maps are Ready
Another factor the transatlantic
aviator must reckon with, Professor
Marvin says, is the defective inhu-
ence of the earth's rotation upon air
plane flight. Objects moving freely
over the earth's surface are DETECTED
constantly to the right
All the knowledge on this and other
factors in the possession of the
Weather Bureau and affecting the
epochal undertaking has been placed
at the disposal of the naval aviators.
With the development of transatlantic
travel by airplane, the Weather Bu-
reau meteorologists hope there will be
for thorough study of the
meteorological conditions affecting it.
There is need" said Mr.. Gregg.
Tor comprehensive campaign of
meteorological and Astrological obser-
vatlons over the North Atlantic in
order that aviators may be given data
for whose accuracy the meteorologist
need not hesitate to vouch. instead of
lnformation based on so small num-
Der of observations, particularly Of
free air conditions, that the deduc-
tions are assumed and not proved"