Evening star., 1925-07-19

Continued from First Page)
tained the wind drift angle from thu
drift indicator.
THE deviation in the steering com
masses of the amphibian planes has
been found to run as high as so de
grees. due to the location of the
switches These compasses Cf thev
work at alb will have to be checked
during the flight with the Navy 5-inch
boat compass which has been placed
in the rear cockpit. p
Party's Compasses.
IF neither OF these magnetic com
passes can be used due to the small
component of the earths horizontal
magnetism las is likely to be the casel
the earth induction compass will be
used. This compass is much more
sensitive than the magnetic compass
and probably viii be useful.
"All compasses will be checked by
the sun compass, and when the sun
is bright this compass may be used
entirely, as the other compasses are
subject to the errors of the
theoretical variation which will
be out as much as or 10 degrees
from the actual variation. In this
case the sun compass will be set TO
the middle meridian of the area to be
traversed, for that will give
approximately a straight lire and only
one course TO steer and the only
change will be that of leeway. Then
every 20 miles the magnetic COM
passes will be checked with the sun
compass and their variations record
ed so that If the sun goes behind a
cloud the return can be made with
the earth induction or the other com
passes.
LAS an aid in navigating. a small
amount of solution of permanganate
of potash will be dropped on the snow
every 15 minutes.
Compass radio bearings will also
be used whenever possible The radio
compass bearings. like the mid-merid-
ian course of the sun compass, is also
approximately a straight line on the
polar projection, and this can be used
very satisfactorily to give cut land
so f1x) with the Summer line of posi-
ton. The latter can be readily ascer-
tained from the Pole as the computed
point, taking advantage of the fact
that at the Pole the altitude and dec
linatfon can for any instant be taken
out of the Nautical Almanac The
altitude of the Observers position can
be obtained with the artificial horizon
seXtant. 1t is sufficiently accurate to
draw the Summer line thus obtained
as a straight on the polar projection.
Check Deviations.
Prior to each fight the deviations
of the compasses for the course to be
steered will be checked at the base by
sun azimuths.
AT Etah the. wings cannot be put
on two of the planes on the steamship
Peary on account of lack of space
Erecting the planes will therefore be
major operation. Approximately ten
days of steady work will be required
to erect planes, make test radio fights,
reconnoitering flights. etc. Another
week, if everything goes well, will be
required to form the advanced base.
1t will therefore be past the middle of
August when the first flight is made
out over the polar sea. The return to
the main base should be about Sep.
tember l.
mo long flights over the polar sea
will be attempted until short flights
have been made to ascertain polar sea
conditions.
"All three planes will be used to
form the base on the polar sea. Two
planes will go together on flights from
this base and the third plane will re-
main at the base as a reserve plane.
All lii &C PldiCo WlIl DS Will
radio.
"At least one of the two planes fly
ing over the polar sea must have a
mechanic t.on board to repair the en-
gine If possible in case of a forced
landing.
''All members of the naval unit are
being required to learn to send and
receive radio.
Plans for Rescue.
1.-THE plane left at the base should
have assigned to it a competent navi-
gator, and before each fight he will
be given all details relating to. the
couse to be steered, so that rescue
work can be competently carried out.
only two persons can go in, each
plane in the polar sea flight. On ac-
count of the extra gasoline tanks nec-
essary, there will not be room for
navigation carrying a third person.
Also, a third person would cut down
too much the radius of action of the
plane.
THE following equipment will be
carried in each plane on the polar sea
flight Emergency tools, gasoline and
oil to depend upon the length of the
flights to be made. At least an hour
and half reserve should always be
carried. A months food supply, pri-