The midland journal. (Rising Sun, Md.) 1885-1947, 1896-07-24
SPEED OF TRAINS.
How It Is Affected by the Diurnal
Rotation Of the Earth.
An Intricate Mathematical Calculation
Upon the Movements of Railway Trains
In Different Directions A
Puzzling Problem.

1t is as far from Buffalo to New York
as it is from New York to Buffalo, yet if
we are to believe the reasoning of Mr..
Alexander Hogg, a correspondent Of
the Railway Gazette, the railway run
can be made more easily in the former
direction because the speed of the east
ward moving train being added to that
of the rotating earth, the reduction of
weight due to centrifugal force is great
er. Wo quote such portions of Mr..
Hogg's letter as do not involve difficult
mathematics:
"In 1891 the New York Central &
Hudson River railroad ran train 436H,
miles In 425 minutes and AZ seconds, or
an average of 61A miles per hour. The
weight of this train was AGO, 900 pounds.
The same company, on September IL,
this year, made tho remarkable run Of
the same 1861 miles in 407 2-5 minutes;
this was an average of 6426 miles per
hour.
''The New York Central, in starting
both times from New York city, IN
necessarily retarded its own speed.
From Albany to Buffalo, due west, the
train encountered not only the prevail
ing west wind, but the force of the
earth's revolution eastward.
lowing to the diurnal rotation of tho
earth, bodies at the equator press
toward the earth with 2ss-2e9ths of the
pressure they would were the earth
deprived of Its rotation. If, therefore,
the rotation Of the earth could be nc
CELEBRATED until 1t took only 1-17th of the
present sidereal day to make a complete
turn or revolution, the centrifugal ten
dency would be increased 17) foldj
that is it would be $50 times as great as
now, and bodies at the equator would
have no pressure downward, or, Us we
say, would weigh nothing. This rate of
revolution would not be sufficient to de-
prive bodies anywhere else of their en-
tire weight.
Nov, let us apply this to railroad
trains. A train running east at the
equator would be lightened as compared
with the weight on still earth. If
running due west, the result would be
Qess). And the difference of weight
between the same train, running east
and west with the same velocity, would
be "a certain) fraction of it's total alb
solute pressure. Example: Taking O
a train running say 10 feet per second,
or nearly As miles per hour, this frac-
tion would not be far from 1-1,6O0tk
part; In running co miles per hour, it
would be 1,2S0th part, and if running
100 miles per hour, or 147 feet per Sec
ond, it would be the 1,765th part, nearly,
and 1t would be greater as both speed
and weight of the train are increased.
The train of the New York Central was
337 feet long and weighed 565,0oO
pounds.
''This calculation, 1t will be observed,
as said, will be true for the equator.
Tho New York Central train ran from
Albany to Buffalo upon about the 42d
parallel of latitude, and " therefore,
this calculation should be corrected for
this latitude, and would be about 7-1Oth
as great"
Other correspondents agree with Mr..
Hogg In principle, though not accept
ing all his mathematics. One of them
ends his letter with the following rather
jocose suggestion:
"It Is we'll known that when the moon
is above us it draws movable objects
away from the earth, and when it is on
the opposite side of the earth it draws
the earth away from movable objects
here, thereby causing the tides. It.
might be well to suggest to the New
York Central officers, that, as the tides
travel from east to west, they may
perhaps offset the disadvantages under
Mr.. Hogg's theory by starting when the
position of the moon is propitious, and,
as they would keep in the tide while
going west, they may still be able to
make fast time going west, even if
the engineers, or indeed the engines
themselves, learn of the disadvantages
of centrifugal force when they are try
ing to make Buffalo" Digest.