Appletons' Popular Science Monthly, February 1900: Vol. 56, November, 1899 to April, 1900Various
Science
Appletons' Popular Science Monthly, February 1900: Vol. 56, November, 1899 to April, 1900
Various
Science -- Periodicals; Technology -- Periodicals
The circuit breaker is a very valuable apparatus, for it frequently
happens that, through delays of one kind or another, a large number of
cars concentrate at one point on the road, and, as all the motormen
are anxious to make headway, they all start up at once at the first
opportunity. If there were no circuit breakers at the power house the
result would be that some of the generators would be greatly overloaded
and perhaps disabled; but, owing to the presence of the circuit
breakers, the actual result is that the circuit is broken, and then
the motormen have to wait until the current is turned on again. If too
many of them try to start their cars at the second trial the current
will again stop. After two or three ineffectual efforts have been made
to start all the cars together the motormen will conclude to go easy,
and set a few in motion at a time. In this way the cars will become
more evenly distributed along the line, and the demand for current at
the point of blockade will reduce to the normal amount, or nearly so,
and the running of the cars will continue without further interruption,
for the current drawn by the motors having been reduced to the average
amount, the circuit breaker will cease to act.
The bus bars and all the connections between them and the generators
and external circuits, as well as with all the instruments, are located
behind the switch board. All these connections are so secured that
they can not come in contact with each other except where contacts
are required; care is also taken to prevent any connection being made
with the iron framing that supports the marble slabs. The front of a
switch board is generally very attractive, the surface being of highly
polished marble, while all the switches and instruments are finely
finished and, as a rule, of decidedly ornamental design.
The switch board might be looked upon as the fountain head from which
the entire operation of an electric railway system is controlled. By
the movement of one set of switches upon it the generators are thrown
in or out of service, and by the movement of another set of switches
the several branches of the road are rendered active or inactive.
IS THE CHRISTIAN RELIGION DECLINING?
BY THE REV. CHARLES AUGUSTUS BRIGGS, D. D.,
PROFESSOR OF BIBLICAL THEOLOGY, UNION THEOLOGICAL SEMINARY.
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