The herald., 1897-06-06

ondary, will produce in it's secondary a
current whose strength is about twenty
times as great, that is, nearly 200 am
peres, but. whose voltage is only about
one-twentieth or 100; the watts in the
two cases are nearly the same, or theo-
retically 10000 watts. CA volt is the
practical unit of electro-motive force.
A watt is the unit of electric power, the
volt-ampere)
A SIMPLE DEFINITION
There is more Ineligible way Of de-
fining volts. amperes and watts, as ap-
piled in electricity, and we will use
again the illustration of a stream of
water flowing from one receptacle into
another, the stream, as before. repre-
senting the wire.
In measuring the water in it's passage
between the two receptacles we must
consider volume and velocity. The vol.
represents the velocity and the ampere
the volume. Now a volume of water of
a certain size flowing at a certain veloc-
ity would empty certain quantity into
the receptacle. The watt represents the
quantity, and as the volume multiplied
by the velocity will give the quantity.
so the volt multiplied by the ampere
gives the watt which as the technical
definition says, is the volt-ampere.
There is also the element of time to
consider. just what the velocity and
volume will produce depends upon the
length of time they operate, and here is
where the watt and itS compounds come
in. A watt is the power developed when
4425 pounds of work are done per min
ute, or the 1-746 of horsepower. 1t is
the result Of volume multiplied by veloc-
ity Ghe volt-ampere). From this we have
the kilowatt, which is 1000 watts, and the
kilowatt hour, which is equal to kilo-
watt maintained for one hour. In other
words, it is volume and velocity meas
ured by time and applied to electricity as
one would measure the current of a
stream of a given size, flowing with a
given velocity for given length of time.
In general, the shorter the wire and
the smaller the number of turns the
greater is the reduction in the difference
OF potential and the greater the current
produced. The reduction is nearly pro-
, portionate to the ratio of the number Of
windings of the two coils
| When one thinks of the Transmission
of power by electricity, the falls of Mag
art at once recur to his mind. To have
harm e'ssed" the linitless power Of the
great waterfall is truly wonderful feat.
The idea first occurred to Sir William
Siemens, president of the Iron and Steel
institute of Great Britain, twenty years
ago. Today street cars in Buffalo are
! run by electric power sent from Niagara
Falls, a distance of 81 miles. In 1886 the
Niagara Falls Power company was or
ganized, and, later, the Cataract Con-
etruction company was formed for the
express purpose of producing the plant.
This company set about finding out the
best method of power transmission, and
the international Niagara commission
was established in London in June, 1890,
| with power to award 1922. 900 in prizes.
Competitive plans were invited, and, as
a result, the different methods of cleo
! trical power transmission were brought
under consideration, and the polypha Sc
alternating current system was finally
| chosen.
SMALL STREAMS AVAILABLE
1t need not be supposed, however, that
the enormous power of Niagara Falls
is necessary to produce electric power.
! A recent number of the Journal of Elec-
tricity said: There is growing ten
dency among the miners and exploiters
Of minee in the western part of the
! United States to utilize as motive power