The star. (Reynoldsville, Pa.) 1892-1946, 1893-08-30

by another electrical machine the speed
and direction Of ship are indicated. This
instrument is connected with the compass In
such manner as not to interfere with its
movements, and at the same time TO show
continuous chart for each fifteen minutes OF
the distance traversed and any variation that
may have taken place In the course.
In submarine telegraphy the Commercial
Cable Company make very instructive and
interesting display. After the several fail
ures OF 1857. 1853 and 1865 OF the attempt to
connect Europe and America by cable. sue
cess was achieved in 1866. Since that yenr
electrical communication has remained un-
broken between the Eastern and Western
Hemispheres. and submarine telegraphs have
multiplied until now tho different lines OF
the globe have an aggregate length of 1870, GOO
miles. The Atlantic Ocean alone is mt pres
ent spanned by ten cables in more or less
continuous use. The Commercial Gable
Company's system Is composed OF two main
cables from Cape Canso in Northeastern Nova
Scotia to Waterville on the southwest coast
OF Ireland. From the latter port the cable is
laid TO Bristol. with aerial lines TO the chief
cities of England, Wales and Scotland. and
another TO Havre with an underground limo
to Paris. At the American end double
cove cable runs from Cape Canso to Rock
port, Mass, with aerial lines to Boston and
New York, and second cable running direct
from Canso to New York. The efficacy of
the blizzard OF 1888, when II was the only
one open from New York to the outer world.
and messages TO Boston and other places
were transmitted by way OF London. The
total length OF cables operated by this COM
piny is G935 nautical miles. In the exhibit
here the whole process of transmitting
messages between Europe and America Is
shown. An artificial cable with all the prop
critics of the real Atlantic cable Is employed
signals sent through II aud received by tho
recording instruments are of the same shapo
and occupy the same time In sending from
one side OF the pavilion TO the other as from
one side OF tho Atlantic to the other.
Visitors arc permitted to send souvenir de-
spatchcs through this artificial cable, and by
watching their course through transmission
and reception, obtain correct idea OF the
whole operation. Many people suppose that
cablegrams are received by means OF flashes
OF light, but II seems that that system Is prac-
tically abandoned. The messages are recorded
on paper ribbon with fine glass siphonno no
thicker than hGir the ribbon moves at tho
rate OF about forty inches per minute and tho
siphon leaves an inky trail clear and legible
TO the operator, but to the ordinary specta-
tor II resembles the outline of mountain
chain In which there are no two peaks alike.
With these recorders speed OF $50 TO 500
letters per minute may be maintained.
Automatic senders are also used. The mes
sage is transcribed upon paper ribbon by
means OF fluctuations, then the ribbon is run
through the automatic sender by this means
light, speed and uniformity are attained.
Some of the instruments for detecting breaks
and injuries to tho cable arc extremely in-
teresting. For example. a machine has been
devised for registering the amount Of ress-
tnncO the current meets with in passing
through the cable. This resistance Is divided
into units called ohms, and the number OF
ohms per nautical milo for any given cable
IL readily dpiucel from the total re-
sistnnce and total mileage. If tho insulG.