So is my literal mind, for several minutes. Then
it enounces:
"But there is no 184 degrees west longitude, nor east longitude, nor
any other longitude. The largest meridian is 180 degrees as you
ought to know very well."
Having got this far, literal mind collapses from the brain strain,
logical mind is dumb flabbergasted; and as for me, I get a bleak and
wintry look in my eyes and go around wondering whether I am sailing
toward the China coast or the Gulf of Darien.
Then a thin small voice, which I do not recognize, coming from
nowhere in particular in my consciousness, says:
"The total number of degrees is 360. Subtract the 184 degrees west
longitude from 360 degrees, and you will get 176 degrees east
longitude."
"That is sheer speculation," objects literal mind; and logical mind
remonstrates. "There is no rule for it."
"Darn the rules!" I exclaim. "Ain't I here?"
"The thing is self-evident," I continue. "184 degrees west
longitude means a lapping over in east longitude of four degrees.
Besides I have been in east longitude all the time. I sailed from
Fiji, and Fiji is in east longitude. Now I shall chart my position
and prove it by dead reckoning."
But other troubles and doubts awaited me. Here is a sample of one.
In south latitude, when the sun is in northern declination,
chronometer sights may be taken early in the morning. I took mine
at eight o'clock. Now, one of the necessary elements in working up
such a sight is latitude. But one gets latitude at twelve o'clock,
noon, by a meridian observation. It is clear that in order to work
up my eight o'clock chronometer sight I must have my eight o'clock
latitude. Of course, if the Snark were sailing due west at six
knots per hour, for the intervening four hours her latitude would
not change. But if she were sailing due south, her latitude would
change to the tune of twenty-four miles. In which case a simple
addition or subtraction would convert the twelve o'clock latitude
into eight o'clock latitude. But suppose the Snark were sailing
southwest. Then the traverse tables must be consulted.
This is the illustration. At eight A.M. I took my chronometer
sight. At the same moment the distance recorded on the log was
noted. At twelve M., when the sight for latitude was taken. I
again noted the log, which showed me that since eight o'clock the
Snark had run 24 miles. Her true course had been west 0.75 south.
I entered Table I, in the distance column, on the page for 0.75
point courses, and stopped at 24, the number of miles run.
Opposite, in the next two columns, I found that the Snark had made
3.5 miles of southing or latitude, and that she had made 23.7 miles
of westing. To find my eight o'clock' latitude was easy.
