The Waco evening news. [volume] (Waco, Tex.) 1891-1894, 1893-05-17
SCIENTIFIC MISCELLANY

SIhAM FOB INOAn w AroNS
Some five years ago NJ. Serpollet
produced his remark able boiler in
which steam is instantaneously
generated in coiled tube, aud
since then he has successfully placed
motors on tricycles and light roai
vehicles of various kinds. In his
latest trials he has demonstrated
the fitness OF stea II power for mill
tary and large passenger wagons.
A wagon tested has a weight when
loaded of $500 pounds carries pas
sengers or merchandise weighing
5000 pounds and travels on ordinary
roads, surrounding slopes Of in
100 without d iliIulty, at the rate of
over ten miles an hour Fuel and
water can bs carried for run of
twenty five miles About nine
p FUNDS of coal and for y-iive pounds
of water are used for each mile the
expense being not m IRE than a third
of that of horses. Striking advant-
ages of the Serpollet generator are
its lightness and the readiness with
which several times the usual power
can be momentarily developed
CITY Dusr Rather startling are
the results of an elab orate iuvesti-
= alton OF the dust of the streets of
Naples, of which DR.. |. Manfredi
has given An account. The number
of microbes of all kinds was found
to average 76l $4,000 per gram,
or about 81 600, 900, 900 per avoir-
dupois ounce. In the cleanest parts
of the city the number was only
10000, 600 per gram, but in the
business thoroughfares the average
rose to 200. 600, 700, and in some
of the air,iest streets il reached
5000, 200, 900. In this vast mass
of life were many disease producing
microbes, and the healthfulness Of
the streets varied with the total
number of microbes. Tests of the
Effectiveness of the dust gave pos
tive results in - per cent. of the
experiments. OF AZ cases of dis
ease induced in Guinea pigs by in
EQUATIONS, with the dust of Naples,
the microbe OF pus was found in 8,
the bacillus of malignant edema in
4, the bacillus Of tetauus in 2, and
the tub orcle bacillus in 3. Not all
city dust has the Notwithstanding
powers of that of Naples, but the
difference is believed to be only ia
degree,
PossIBII ITIES OF THE ELECTRIC
RAILWAY. Assuming that the or
binary laws of air resistance hold
good at very high speeds, DR.. FL
ward Hopkinson calcula es that the
power required to propel an ordin
airy train 200 feet long at 200 miles
per hour against the resistance of
air alone, apart from the FRACTIONAL
resistance, would not be less than
l, 700 horsepower. Though there
is nothing to prevent the consruc-
tions of electric locomotives ca
pable of d veloping this or even
greater power, the strength of the
materials at present at command
will set limit to the speeds which
may be obtained. Speaking of the
ultimate efficiency Of the machines,
DR.. IIopkinson started with the IS
miliar l2,OO),0 900 foot pounds, the
energy Of pound Of coal, showed
the minimum loss in each step, ii rst
in the boiler, then in the steam en-.
CINE, generator dynamo, conductors,
locomotives, in the dead weight of
the train, till finally he arrived at
the energy expended on the pas
senger himself, which is 1873 900
foot pounds, or but little more than
one per cent. of the energy at the
start. 1t is true, ind sed, he con
clude', that transportation is more
economical process than Lighting
with incandescent lamps, in which
the final efficiency is about one. half
per cent, but whether in lighting
or in traction, when we consider
that 90 parts are now wasted for
one part saved, we may realize that
the future bias greater possibilities
than anything yet accomplished