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scientificamerican.com/magazine/saPeople Movers
Cities are well served by extensive transportation networks that move people and goods into,
out of and around urban conglomerations on a daily—or hourly—basis. But there is a question
of how to power these people movers. The London Underground, opened in 1863, had coal-fired steam en-
gines pulling gas-lit cars along “tube” tunnels. It must have been spectacularly grimy. San Francisco’s cable
cars grab hold of moving cables under the street, which are powered by static engines. Alfred Ely Beach,
an early editor in chief here, demonstrated an underground railcar puffed along by air pressure in 1870 ( 1 ).
Entrepreneur Elon Musk’s proposed Hyperloop plans to zip railcars through a near vacuum inside a tube.
As networks of rails over and under the ground expanded with cities, they were melded with electric power
grids ( 2 ) to create faster and cleaner urban transit systems. These networks now serve hundreds of millions
of riders a day worldwide, and their efficiency may help mitigate climate change as populations grow. — D.S.1970
Lunar Laser
Reflector
“In July of last year the astronauts
of Apollo 11 placed on the surface
of the moon an array of prism-like
reflectors that has made it possible
to measure the distance between
the earth and the moon with an
accuracy approaching six inches.
The important quantity, however,
is not the absolute distance be-
tween the earth and the moon but
the variations in distance mea-
sured over a period of months and
years. Such variations can be stud-
ied to answer important scientific
questions, such as how the mass
inside the moon is distributed, the
rate at which the continents on the
earth are drifting toward (or away
from) one another and changes
in the location of the earth’s North
Pole (which shifts in response to
unknown forces). A more funda-
mental question than any of these
is whether the gravitational con-
stant is indeed constant or wheth-
er it may slowly be weakening
with the passage of time.”1920
Calling Mars
“The recent sug-
gestion that the Martians are try-
ing to send wireless signals to us
may prove groundless, but it has
at least called public attention to
an important subject. The idea of
exchanging thoughts with intelli-gent beings on another planet is
too alluring for the human imagi-
nation to resist. To bring the pub-
lic to the necessary point of enthu-
siasm, they must be assured that
an exchange of signals will rapidly
develop into an exchange of ideas
on any and all subjects of common
interest. We want to talk over
our scientific, social and religious
notions with the Martians, and
if they have a civilization far older
than ours we want to learn from
them truths that will help us in
our own difficulties.”1870
Pneumatic
Subway
“The doors of the Beach Pneumatic
Transit Company were thrown opento the public for the first time
when an ‘Under Broadway Recep-
tion’ was given, by special invita-
tion to the State authorities, city
officials, and members of the
press. All the prominent personag-
es of the city and State were pres-
ent, and the inspection of the
works gave the greatest satisfac-
tion. The various daily newspapers
have published long accounts
of the event, which has produced
quite a novel sensation in the me-
tropolis. The New York Herald says
‘it was virtually the opening day
of the first underground railway
in America.’ ”
this demonstration project was
designed and built by Alfred ely Beach,
then editor of this magazine.1870: The Beach pneumatic subway,(^1) an early transportation experiment.
1970
1920
1870
MARCH
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CELEBRATING
YEARS
1915: Workers install overhead electric power lines for suburban commuter trains in Philadelphia.
SCIENTIFIC AMERICAN,
VOL. XXII, NO. 10; MARCH 5, 1870 (
1 );^
SCIENTIFIC AMERICAN,
VOL. CXIII, NO. 5; JULY 31, 1915 (
2 )
EPIC TALES
2
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