St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1889-12-21
with tho less Suppose that a person
,ay, f,,n,, a. -

and his mind is stretched ever the en-
tire 5, 2S0 feet in ono instantaneous.
accurate comprehension. can he do j.
with second mile in addition SO that
he comprchcnds it as accurately as the
first? To ask tho question is TO answer
it in the negative. We think distances
as indefinite extension, or rs vague
bignesses. with greater or less pro-
portion to each other. and with
comparisons based on mathematical
terms. Though the traveller knows
that it is three thousand miles. say. in
round figures. from Boston to San
Francisco. yet he knows it in expert
encc only as a very long journey.
Doubtless it would be impossible TO
find man who would say that he
comprchends it as just thirty times rs
far AS from Boston to Springfield.
With no miles for his unit. or with
the distance from Boston to Springfield
as his unit wouldnhe not be likely to
say that the transcoutinental trip was
much more than thirty units in that
scale?
We are familiar. thanks to the as
tronomers. with figures representing
prodigious distances. and it is perfect
ly safe to saw that those figures are
nearly meaningless to us, save as they
represent an extension indefinitely and
inconceivably big. We are taught that
the moon is 23S,O00 miles from the
earth, to speak in round numbers. and
that the earth is 81, 900. 600 miles from
the sun. Then it is said. rs if we could
comprehend ii. that the earth has a
velocity in its orbit of nineteen miles
in a second. We are told regarding
the velocity of light that it flies
through space at about 100000
miles second. and we accept it rs
il we understood it, together with the
companion statement that light from
the nearest fixed star requires over
forty years to reach us, while the
scintillations from the telescope stars
must have started on their ethereal
fight hundreds or thousands of years
before reaching the terrestrial be-
holder. But. though the figures are
true, yet they convey but little mean
ing to the human mind.
Suppose We try to get an idea Of
speed by joining our two ideas of the
distance traversed and the time occu-
pied. with the understanding that
every foot of distance and every Sec
ond of time is rated at its full value.
The person who tries the experiment
will very soon find tnat he has reached
the limit of his mentL powers. He
may know that lightning moves with a
certain velocity a second; but let him
attempt to comprehend the speed Of
the fash from the thunder cloud. ard
he will see partially how he fails to
comprehend the object OF his attcn-
tion. 1t may be fairly doubted whether
the average educated man can
grasp a rate Of speed much be-
yond that of a fast express train and
comprehend its value Tho mind
might see that one velocity was much
more than another. but it would prOba-
bly, fail t. reach an accurate judgment.
Now. the highest railroad speed with
which the travelling world is familiar
is that on the London & Northwestern
railroad. which makes the 400 miles
from London to Edinburgh in eight
hours. and on a portion of the distance
attains the speed Of seventy-five miles
an hour.
With that speed as unit. see what
mean these celestial distances which
we are accustomed to mention famil-
iarly. as If we understood them. We
think of the moon as near US. So it is
compared with the sun; very close
neighbor compared with the telescope
stars. But if our locomotive were able
to fly to the moon at scventy-five miles
an hour. making no stops for water or
fuel. day or night, how long would ii
be before the man in the moon could
pass the time Of day with our engineer?
1t would DO S.17S hours. or continu-
Gus run. day and night. of 13O of
our earthly days. That is. ii our
locomotive should start New Years
morning at this furious speed of sew
enty-five miles an hour (and that it is
furious no one who has seen a train
move even fifty miles an hour will
question). and continue without an
instant's slackening. it would reach
the end of its trip the 10th of May!
That may help in our comprehension
Of the distance, in common language.
but docs it not also emphasize the fact
that such n distance is absolutely in
comprehensive in the true meaning OF
the word comprehend?
But how is it with the distance to
the sun? II so much time is needed to
reach the moon. it will take years to
reach the sun. Yes. it will-years and
years. But how many? 1t is a mere
question of mathematics. If the sun
is %. 900. 900 miles from us, and our
locomotive travels seyenty-fivc miles
an hour. it will be l, 226. 666 hours on
the journey, or 81. Ill days of twenty
four hours each, or 40 years In
other words. had the locomotive
been l.nown in the middle OF
the last century. the fight could
have been begun twenty-five years be-
fore the battle of Bunker Hill. and the
iron horse could have been thunder
ing down the ages" cver since. day
and night. at this terrific speed. and
not have reached the sun yet. What
a distance is that! Yet tha. is but the