A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2014 Dec 13, 17:18 -0800
I didn't have to look very far. Try looking in the log of the R34 http://archive.org/stream/logofhmarjourney00maitrich/logofhmarjourney00maitrich_djvu.txt . What did we do before Google?
OUTWARD JOURNEY 43
round view of the Atlantic since we started. Sea
is very blue, a biggish swell, and many white
horses. Hope that, with this good visibility,
we may at last see a passing ship.
One of the crew (a rigger) is ill. Temperature
102. Confined to hammock and dosed with
quinine and salts.
Running on forward and after engines only, and
resting both wing engines. Height 1100 feet.
We cannot tell our height above sea accurately,
as we don't know what the barometer is reading.
Our aneroid shows height as 1200 feet. Scott
thought it more likely to be 1500 feet, as one
cannot well assume that the barometer here on
the surface of the water is the same as the baro-
meter was when we left the ground at East
We now try the experiment of lowering an
instrument known as a sea-level aneroid, and
specially designed to record atmospheric pressure
readings, down to the surface of the water. The
ship is not slowed down for the purpose in any
way, and as this has not been tried before success
Result is no good, as the instrument shows
exactly the same reading on reaching car again
44 THE LOG OF H.M.A. R 34
as it had before starting. It had undoubtedly
recorded the reading on surface, but got jerked
(being a very sensitive instrument) on the quick
Until we know our exact height above the sea
we cannot plot our exact position, so until we
speak a ship in our vicinity and get her barometer
reading we still lack means for such a calculation.
Some suitable method of getting this information
must be perfected before we do any more long
Scott works out our height above the water in
the following way
The airship is throwing a very dark shadow on
the surface of the sea on starboard side almost
immediately underneath the ship. By taking
with a sextant the angle subtended by length
of the shadow, and knowing the length of the
shadow to be 640 feet, he gets the true height.
In this case the height works out at 2100 feet,
whilst the aneroid gives us only 1200 feet a
variation of 900 feet.
12.45 p.m. Durrant is speaking s.s. Canada
on our W.T. spark set. Another W.T. operator
(Corporal Powell) is trying to get her on the
directional wireless, so that we may know in
OUTWARD JOURNEY 45
what direction to look for her. All we know at
the moment is that she is somewhere within 120
miles of us, and bound for Liverpool.
She gives her position as follows : " Long.
51 16' N., Lat. 39 42' W. (or sixty miles S.S.E.
from us), barometer 30.8, rising. Wind and sea
moderate from S.E. DAVIS, Master."
Her wireless operator tells us that great
enthusiasm prevails on board, and that every one
is hoping to catch sight of us. This feeling is
mutual, but, although we do our best to get her
on our directional wireless, besides gazing through
our glasses in every direction, she remains just
beyond our visibility.
Scott now brings his ship down to the 1200-foot
level, to try and find a more easterly trend in the
The reading on s.s. Canada's barometer is of
the greatest value, and is exactly the information
of which we are in need. We can now work
out our true height above the sea, and con-
sequently fix our exact position. Her barometer
on surface reads 30.8, whilst ours in the ship is
29.7. This shows a difference of 30.8-29.7, or
1.1 inches. Remembering the rule that for
every 1000 feet you rise the barometer falls one
46 THE LOG OF H.M.A. R34
inch, we get our height as 1000 feet, which tallies
almost exactly with Scott's estimate of 900
feet inaccuracy mentioned above. It is quite
possible that Scott's calculation of 900 feet may
still be dead accurate, as s.s. Canada is some fifty
or sixty miles away, and the change in barometer
over that distance may well work out at 100 feet.