Watertown republican. [volume] (Watertown, Wis.) 1860-1906, 1883-07-04
CURIOUS, SCIENTIFIC AND USEFUL.
EXPLOSIONS OF COAL DUST.

" IhO kJOSALOo VI tJONGeE " III carly 1aluS
III the air twenty feet; with the coal dust
IN suspension, the fame runs double the
distance, and with small proportion OF
gas and dust it goes still farther. After
the fire has started the production Of
coal gas by the decomposition Of the
coal dust would probably be so rapid
that the oxygen OF the air would soon be
used up to form carbonic acid, water and
sulphurous acid The dangers are in
! creased by the presence Of minute guam
titles Of pit gases, and dusts which re-
! fuse to inhame an atmospheric air Will
do SO if small quantity of coal gas Oh
pit gas be added.
| ELECTRIC LIGHTS FOR LOCOMOTIVES.
Electric lights for locomotives appear
to have given considerable satisfaction,
| the experiments made on one OF the
French railways having some time since
proved its peculiar advantages for such q
purpose. According to this system, the
lamp is placed in front Of the engine, SO
as TO light the permanent way to an ex-
tent equal to all needs and exigencies,
The advantages mentioned in its favor
are, among others, chat it burns stead
lily, even when the train goes at express
speed; that the light does not interfere
with the visibility or distinctive colors Of
the signals; and that neither the en-
CINE drivers, nor employees Of the train
carrying the light, nor those Of other
approaching trains are dezzled by IT.,
and thus the ordinary dangers arising
from the source are almost entirely
avoided, 1t is stated that the drivers
are by this means able to see the line
distinctly for a distance of 800 yards
ahead.
AN AUTOMATIC CLOCK,
On the London Stock Exchange is on
automatic clock which has for six mSnths
performed very well. The winding APP
paratus is designed to be fixed in Chin
ney, or any other place where toler-
ably constant current of air can be re-
lied on. BY means of a reversed train of
multiplying wheels this windmill is con-
tinually driving a Hughens endless
chain rent0ntoire, a. device familiar to
clockmakers. a pawl acting on wheel
prevents the motor from turning the
wrong way, and by simple arrange
ment, whenever the weight is wound up
| tight to the top, the motion is checked
by friction brake automatically APP
piled to the thermometer by the raised
weight lifting lever. When the weight
| is thus raised TO the top, the clock has
| sufficient store of energy to go for eight
| days or more, so that it is by no means
| dependent on a regular current Of air.
! This sort of clock has been for some
time used at the Belgian railroad sta
! tons.
| OYSTER LORE.
According TO the report OF the shell
fish commission in Connecticut, there
are over 80, 900 acres OF oyster-g grounds
under cultivation and under the jurisdic
! ton of the state. new mode OF cult.
walton, or capture of epat for seed or
muddy bottoms has been invented al
| Grotop, Birch trees about twenty feet
in height, ana three or four inches IL
| diameter at the butt, are thrust about
three feet into the mud, with the tops
under the surface of the lowest water
and inclined at an angle Of some 40 de-
gIees with the current. The floating
spat attaches Itself to the branches anC
grows rapidly; single bush affording
In few months, five TO fifteen bushels
of seed oysters, none of which would
survive settling on the muddy bottom
An absurd claim WIS made that these
submerged bushes produced scarlet fever
and diphtheria, and many have been de
stroyed; but the plan has recently re
ceiYed legal recognition, and, with pro
per effort, can be made to produce mil
lions Of bushels OF oysters where is nov
only waste ground.
ELECTRIC MOTOR FOR BALLOONS.
NJ. G.. Tissandier has described to tn
Paris Academy of Science his new cleo
trical motor for balloons. It consists O
screw propeller with two helicoida
blades nearly ten feet in diameter, Sic
mems dynamo-electrical machine of ney
design, and a light bichromate- of-pot
ash battery. It is intended to prope
an elongated balloon of about /, 00
cubic yards capacity. The frame of tn
screw propeller weighs fifteen and hal
pounds, is stretched with silk varnisnet
with India-rubber lacquer, and kept tau
by steeI-wire stretches. The dynamo
: electric machine has four electro. mag
nets in the circuit and the frame part
are of cast-steel, SO as to bring tn
weight down to 121 pounds. I
drives the screw by gear, whicl
reduces the speed in the proper
ton Of 10 to L; thus, if the coil makes
1,200 revolutions minute, the screy
makes 120. It gives out 900 foot-pound
per second with useful effect of 55 pc
cent. The bi-ch1omate battery gives
better yield than accumulators. of tn
same weight. It consists. of an elemen
divided into four series, and arranged il
tension. The element consists Of a.
ebonite cell holding four litres-or 0.8
gallon-and containing ten plates 0
zinc and eleven cakes of retort carbon
arranged alternately. The Immersed
surface OF the zinc is one-third that o
the cartoons. This battery charged Will
lightly concentrated and very acid SO
luton, is constant for two hours Tn
liquid becomes heated as it is impover
ished, and the duration of activity ma,
be prolonged by the addition of chromi
acid.
NEW PROCESS OF COLOR PRINTING.
A step Of some Importance apparent,
, has been made IN the art of polychro