Installment twenty-three

Captain Mann has been sharing with the crowd an old article about
the date line. Now he continues with another example from the article.
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Installment twenty-three:

"A common illustration, which may be observed almost any day, may serve
to make it a little clearer to some. Think of a freight train a quarter of a mile
in length. It starts and moves along slowly the distance of its own length, or
a quarter of a mile, bringing the rear of the train when it stops, to the same
place where the head of the train was when it first started. Suppose now that
a brakeman started from the rear of the train, when the train started, and
walk along the cars toward the front, his rate of motion being the same as
that of the train itself. When the train stops, he has reached the head of the
train. The train has carried him a quarter of a mile and he has walked another
quarter on his won. So now he is half a mile from where he started. But now
suppose another brakeman, when the train begins to move, starts from the
head of the train, and walks toward the rear at the same rate of motion. When
the train stops, he has reached the rear, but his motion was being opposite to
that of the train, has just balanced , or canceled for him, the motion of the
train; so he finds himself, in space or compared with surrounding objects,
just where he was when the train started. So brakeman number one who
walked a quarter of a mile actually advanced a half mile distance, but the
second brakeman, who also walked a quarter of a mile, has advanced no
distance at all because the train was moving in the opposite direction. The
same principle applies to the earth's motion and those who are traveling
around the globe. One going eastward adds a day to his reckoning, while
one going around westward loses a day out of his count."
Mr. Severance, the merchant, now asked for the privilege of supplementing
Captain Mann's extract by one which he had preserved. He read as follows:
"The reason for adding or dropping a day at the date line will become
apparent upon brief examination. It is always sunset at some point on the
earth. In the same manner, it is always sunrise, and noon, and midnight at
other points at the same time. Let us imagine that we could travel around
the earth as rapidly as the earth revolves upon its axis, and we start out
from London at sunrise on Tuesday morning and travel west. It would
remain sunrise of the same day with us all the time. Yet when we come
to London again we should have to call it the next day; for those who
remained there would have had noon, sunset, midnight and now would
have their second morning, which would be Wednesday. Therefore we
must change our reckoning so that at that instant, in any place east of
London, we would call it Tuesday morning; but at any point west of that
line, it would be Wednesday. That would be the place where the day would
change, but for convenience, men have chosen a line that passes through
no habitable country, and have fixed that point as a place where the day
would change.
By this arrangement, each day is measured off by one revolution of the
earth; and when it is finished, it is discharged from the calendar, and a
new one takes its place at this point. Hence, wherever we may be on the
face of the earth, the day comes to us with its full measure of twenty-
four hours, and then is succeeded by another of exactly equal length. It
is true that by our traveling east or west, the length of day may to us be
varied; but at the date line, these variations are all rectified. In circum-
navigating the globe, we find that we have done so without disarranging
our calendar.."
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To be continued...