The news and herald. (Winnsboro, S.C.) 1877-1900, 1879-08-12
SCIENCE.

"A PolySphenic Ship.-.For the last six
years, the Rev. G. NJ. Ramus, Rector
of East Guildeford and Playden, Eng
land. has held his invention of the poly
sphcnc ship at the disposal Of the Ad-
miralty. This vessel, it is calculated,
will skim the seas at the rate of forty
miles an hour or more. The word
eskimo discloses the secret Of the idea,
for the invention Is mainly based on
the fact that it a vessel can be made
by the mere force with which 1t moves
to ride over the waves instead Of driv-
ing through them, there Is Il prima
facie reason to believe that Il much
higher speed than anything yet reached
will be achieved. The principle of Mr..
Ramus's invention consists in making
tho bottom of the vessel Il series of in
clined planes. In 1872 Mr.. Ramus
made a model having its bottom COM
posed of two parallel and consecutive
inclined planes; Or the vessel may be
described as made of two wedges, the
thick ends Of which are placed abaft the
thin ends. There is thus in the centre of
the vessel ridge where the thin end
Of the stcrnmos1 wedge abuts against
the thick end of tho foremost. Any
floating body thus shaped must, when
driven forcibly through the water,
tend to rise, and If tho speed Is high
enough it will rise on the surface in
stead OF driving through the water.
These facts were demonstrated by some
rough experiments made in the pres
ence Of cretlitable witnesses. The pro-
pelling power III thes experiments was
u six ounce rocket. In one trial the
model weighing pounds 3ounces, ran
a distance Of lO5 yards in 3 seconds.
In another it ran 4S0 feet in ~ sec
1,ts,S ,,t, l,,l L,rv
strong breeze, but In spite of this the
the deck was found to be dry. The
principle underlying these models, says
Ihc Mechanic, may be taken advantage
Of to construct wcdgc-shapcd ships. for
it has been demonstrated that the resiS-
tance to such vessel, which 1T first i'll
creases about rs the square of their yo-
lOCity, decreases as the speed Is aug
mented, until after 4 certain period
there Is no further increase of resis-
tance. Given the required machinery,
then, for propclling tho poIysphcnlc
ship and there seems to every pr0ba-
bility that speeds of forty miles IN
hour or more can be attainCu.
The Lightning- Rod. - The st. Louis
Academy OF Sciences has been throw
ing light upon the lightning-rod, con-
CCfUluR WHICH,, SulU ITOlcSSOT IN pllCf'
there are many popular delusions.
One is, that If one or two rods contain
ing an equal amount of metal be hol-
lowed out, thus giving it greater. eX-
pansc, It's conductive power would be
greater than that of the other. The
truth is that they would be equally
good conductors. Another erroneous
impression which the Professor pro-
cceded to dispel was that a current OF
electricity runs along the surface Of Il
wire. In reality it extends through
the entire wire when the circuit is
made, Mr.. Niphcr said, but while the
circuit is closed, it accunlulatcs upon
the surface OF the conductor. a strong
point made was that lightning-rods 10
not attract the lightning. They arc
splendid conductors, anu much better
than wood or air, and lightning strikes
them because they offer the least rcsis-
tancc to the passage Of the electric cur
rent. Ii makes no difference whether
point be Oh a lightning-rou or not, so
far AS the protection of buildings is
concerned. The positive cleClr. city in
the earth will flow along the wire and
accumulate at the p0lnt, If there DC
one, making the tension and the con-
ducting power greater and enhancing
the probability OF lightning striking
that rod In preference TO another
which has no point but has the poitivc
currnt disseminated through it
equally.