(From “The Rectory Umbrella”)
Half of the world, or nearly so, is always in the light of the sun: as
the world turns round, this hemisphere of light shifts round too, and
passes over each part of it in succession.
Supposing on Tuesday, it is morning at London; in another hour it would
be Tuesday morning at the west of England; if the whole world were land
we might go on tracing[31] Tuesday morning, Tuesday morning all the way
round, till in twenty-four hours we get to London again. But we _know_
that at London twenty-four hours after Tuesday morning it is Wednesday
morning. Where, then, in its passage round the earth, does the day
change its name? Where does it lose its identity?
Practically there is no difficulty in it, because a great part of the
journey is over water, and what it does out at sea no one can tell: and
besides there are so many different languages that it would be hopeless
to attempt to trace the name of any one day all the year round. But is
the case inconceivable that the same land and the same language should
continue all round the world? I cannot see that it is: in that case
either[32] there would be no distinction at all between each successive
day, and so week, month, etc., so that we should have to say, “The
Battle of Waterloo happened to-day, about two million hours ago,” or
some line would have to be fixed where the change should take place, so
that the inhabitants of one house would wake and say, “Heigh-ho,[33]
Tuesday morning!” and the inhabitants of the next (over the line), a
few miles to the west would wake a few minutes afterwards and say,
“Heigh-ho! Wednesday morning!” What hopeless confusion the people who
happened to live _on_ the line would be in, is not for me to say. There
would be a quarrel every morning as to what the name of the day should
be. I can imagine no third case, unless everybody was allowed to choose
for themselves, which state of things would be rather worse than either
of the other two.
I am aware that this idea has been stated before--namely, by the
unknown author of that beautiful poem beginning, “If all the world were
apple pie,” etc.[34] The particular result here discussed, however,
does not appear to have occurred to him, as he confines himself to the
difficulties in obtaining drink which would certainly ensue.
[31] The best way is to imagine yourself walking round with the sun
and asking the inhabitants as you go, “What morning is this?” If you
suppose them living all the way around, and all speaking one language,
the difficulty is obvious.
[32] This is clearly an impossible case, and is only put as an
hypothesis.
[33] The usual exclamation at waking, generally said with a yawn.
[34]
“If all the world were apple pie,
And all the sea were ink,
And all the trees were bread and cheese,
What _should_ we have to drink?”