The L'Anse sentinel. (L'Anse, L.S., Mich.) 18??-current, 1892-05-07
SCIENCE AND INDUSTRY.
INTERESTING DISCOVERIES IN
THE FIELD OF SCIENCE.
Compressed Air as a Motor--'Twiii
Sell Stamps--Light as a Meas
urer--SavIng Life Bv Eleo-
trlclty.
Compressed Air as a Motor.

/ compressor AR as q mOtOTs
The evolution of the street railway
from the horse car to the perfected
cable, steam, electric, or compressed
air motor Of the coming century is not
yet completed. As to speed, cable,
elevated, and electric roads would
answer very well the needs OF city
communications were it not for the
frequent blockades and breakages OF
the cable, the unsightly appearance
OF elevated roads, and the disinclina.
ton to work that occasionally afflicts
electric roads.
What the perfected motor will be,
whether cable, steam, electricity, or
compressed air, it is not possible at
present to say. Experiments with
each are inprogress in nearly all the
large cities OF the world, but as yet it
is merely balancing of advantages
and disadvantages in which mono of
the motors have as yeta decided SUI
periority.
Compressed air has been used as a
motor on the Nogentais tramway
near Paris for the last three years
with very satisfactory results. Con-
| sui General Rathbone, of Paris, in his
consular report thus summarizes the
| advantages of this motor in street
railways:
/. The motor does not emit smoke
or not gases, and is almost noiseless.
2. AS great a speed as is desirable
or necessary is attained.
3. A special track or overhead ap-
| plia nee is unnecessary.
A. Being very light the motor engine
as used at Nogentais can easily be
handled on steep grades.
5. Simple in form, it does not
brighten horses as machinery in the
front platform is almost invisible
from outside.
9. A possible explosion of air reser-
or super-heated water.
z. Maintenance in repair is very
simple.
8. Only one person is necessary
for managing the machinery, and he is
not necessarily skilled engineer.
8. AS in tho cable number of
trailers can be used without q separ-
ate motor.
The explanation of the system is
simple, the reservoirs OF air being
charged with air compressed to 40 or
45 atmospheres, heated to high tenn
perature, and saturated with mois-
ture in q vessel called the vouillotte,
or heater, and from thence passes to
double-expansion engine, where it
acts like steam in moving the piston
rod. The expense OF the motor is
about 9h cents per mile, The shape
OF the car is similar to all French
street cars, having an interior and
upper part, the steps being arranged
to make connections with the extra
car when attached. The air reser-
voirs, nine in number, are parallel to
the axles of the wheels Of the train,
are made OF steel and tested for 80
atmospheres. The movements OF the
machinery are said to be very simple,
but the system is certainly more COM
pick than the cable.
Twill Sell Stamps.
A Buffalo company has placed on
exhibition the latest automatic ma
chine. 1t is called the automatic
stamp accommodation, and is for the
purpose OF supplying stamps to any
body who may need them and has
the price. The machine is of the
nickel-in-the-slot variety, and fur
nishes either one or two cent stamps,
as may be desired. 1t resembles one
of the familiar chewing-gum machines
and has two slots. On the one side
the slot is for 2-cent stamps and it is
necessary to feed in two pennies, when,
upon pressing q knob a small book
will fall out and in the book the stamp
will be. The modus operandi for a
1.cent stamp is precisely the same, ex-
cept that it takes but cent.
The stamp machine is strictly hon.
est. When it is empty there is an au-
tomato arrangement which closes
the slots and makes it impossible
to feed pennies and receive
nothing therefor. The machines
are very handsomely gotten up,
and after one or two improvements
have been made will at once be put
out. The only other stamp machine
which is used at all is one which gives
two stamps for nickle. The adyan-
tage of the new machine is that it fur
nishes both l and 2 cent stamps and
charges no more for them than their
face value. The machines will be
placed in any public place which may
seem advantageous, and will be sup
piled free. The company will make
its money out of the advertisingin the
little books in which the stamps are
placed. These books are small pam
phlets and contain large variety of
interesting matter. There are thirty
five in the series, and they are on sub
jects ranging from hints on nursing to
a guidefor the laundry. OF course the
number of subjects on which the
books can be written is unlimited,
and there will probably be many more
than the thirty-five volumes that are
now used.
Light az Measure.
The accuracy OF modern scientific
processes is indicated by the proposal
to employ the wave length Of light as
A L. L.