The daily star-mirror. (Moscow, Idaho) 1911-1939, 1919-05-06
the land because the air above the sea
L.. L. El.z-,,a

the land because the air above the Sc;
is less turbulent or "bumpy."
Marine weather MAPS" said Mr.
Gregg, in a recent paper read before
the Philosophical Society of Washing
ton, ''shows that at an altitude OF
500 to 1000 meters 1000 to 1920
feet, approximately conditions are
favorable for an eastward trip ap
proximately one-third of the time
the percentage being slightly great
er along the northern than along the
southern route At greater attitudes
the percentage of favorable days ma
terially increases, especially along
| the northern route. For the west
ward trip the percentage of favorable
days is SO small as to make trans
Atlantic flight in this direction i'm
practicable until the cruising radius
of aircraft is increased to such an ex-
tent that they are relatively indie
pendent of wind conditions.
"All things considered, conditions
for an eastward flight are most ia
vorable along the northern course;
for westward flight they are most
favorable along the southern course;
that is, the prevailing westerlies are
less persistent along this course than
farther north.
Little Choice in Season.
There seems to be little choice as
to season, for, although the prevail
ing westerlies are stronger in winter
than in summer, yet on the other
hand, stormy conditions are more
prevalent in winter, and the net re-
suit is about an equal percentage of
favorable days in the two seasons.
Moreover, the greater fog percent
age in summer just about offsets the
greater percentage of cloudiness IN
winter. Fog is disadvantage chief
ly because of its interference in max
ing observations with drift indicators.
The Newfoundland fogs in general
are of small vertical extent and do
not extend far inland. They should
not, therefore, prove a hindrance to
landing, if the landing is located some
distance from the coast"
Near the Irish coast the percentage
of days on which fog occurs varies
from about 10 per cent in summer to
; per cent in winter, in contrast to the
Newfoundland average of so per cent
in winter. Fogs rarely occur near
the Azores or between them and Por-
tugal.
The statements made by the mete-
in relation to airplanes ap-
ply equally well to airships, they say.
however, because of their
greater capacity for fuel and their
of motor power to sus-
tain them, are capable of remaining
in the air a relatively long time and
are not so vitality dependent upon
favorable wind conditions.
Airplane COmpasses Lose Precision. :
Compasses have been found to lose /
much of their precision on airplanes,
and on trans-A tlantic flights it is be-
ieved they would be somewhat near
Useless. The oscillation Of the plane
itself is a large deterrent factor, and I
others are the attraction of the mo-
or or machine material for the need
e, and the empracticability of max
ng corrections while making flights
At highspeeds. Under clear skies
,eXtant observations make possible
he correct determination of positions
tut in cloudy weather the compass is
he only guide unless the aviator can
ly high enough to get above the
LIQUIDS. 1t is believed necessary that
transatlantic airplanes, in the pres
mt stage of development, should be
n constant touch with ships that
ouid indicate positions by wireless.
developments in wireless have made
possible to tell the direction from
which an air message is sent.
The difficulty of accurate flight
would be greater if the airplane were
lining at a comparatively small is
and, such as the Azores, instead of
roland or the coast of Europe.
Professor Harvin points out that
, would be quite possible for an avi-
tor. flying over the uniform surface
f the ocean, to turn his machine I'M
and fly away from his OBJ
ect. Also, if his machine, making
speed of go miles an \
our, should run into a head wind
80 miles an hour, he might stay in
in the same position over
he ocean. On land an aviator can
I'll whether wind is aiding or re-
arding him, but over the changeless
"a, unless there were ships within
is vision, he would have little or
othing by which to guage his pro-
reSS.
Earth's Motion DETECTS Airplane.
Another factor the transatlantic
viator must reckon with, Professor
[arvin says, is the defective influ-