Bedford inquirer. [volume] (Bedford, Pa.) 1857-1884, 1870-04-15
BEAooNs AND SIGNALS.

BEACoNs AND SIGNALS
Concerning the possibility Of seeing arti-
fetal light at a great distance, the Ordinance
Survey furnishes the most interesting and
Trustworthy experience. 1t is necessary
10 the highly scientific details Of such sur
yeyi that certain elevated spots should be
rendered visible at great distances one from
another, for the determination of large tri-
angles Of which the angles can be accurately
measured The custom has generally been
to wait for clear sky, and then to employ
a powerful telescope to view the summit of
a,distant mountain. When Colonel Colby
was placed IN charge OF the Irish Ordinance
Survey in 1924, be at once saw the necessity,
N so misty climate as that Of Ireland, Of
1 employing some intense artificial light to
render the stations visible one from another.
Lieutenant Drummond had, shortly before
that period, conceived the idea that the al
most uDapproachable light Of ircandescent
lime, reflected from parabolic mirror, might
be used as night beacon, aud Cylby and
he thereupon proceeded to test the theory
in practice. A particular station, called
Sieve Snaught, in Donegal. had long been
locked for from Davis Mountain near Bel
fast. eistaneO of siTtg-six miles The
mist. day after day, was too great to permit
It to be seen; and then Colby determined to
employ Drummond's light The night Sc
lected was dark aud cloudless, the mountain
was covered with snow, and cold wind
gushed across the wiutry scene. Colby was
on Davis Mountain, Drummond on Sieve
Snaught; on the instant the latter displayed
bis lime light, the former saw it as brilliant
star, shining over the intervening Lough
Neagh. 1t was a complete success Of /
beautiful experiment The light was pro- /
duced By lacing small ball Of lime, only
quarter Of an inch in diameter, in the focus
Of a parabolic mirror, aud directing upon it 1
through a flame arising from alcohol
stream of oxygen gas; the lime became white !
bot, giving out light. the intensity Of /
which alike surpassed conception aud de
scription. 1t is literally true that tiny bit /
of lime was visible sixty-six miles distant;
for it was not fame that was seen, but the /
actual white-bot lime Itself The experi, ,
ment having once succeeded, il was applied /
in various ways One Of the famous tri /
angles established by Colonel Colby had for /.
It's three points Ben Lomond 10 Dumbarton-
shire, Cainsmuir in Kirkcubbrightshire /
aud a mountain in Antrim in Ireland; each /
station was rendered, by the lime light, /
visible from each Of the other two, although /
the distances were sixty seven, eightY-one. I
and ninety five miles respectively. On an /
other occasion be even exceeded a hundred
miles, by this wonderful light.
The ordinance surveyors have also sue /
ceeded in rendering their far distant stations |
visible in the daytime, by a peculiar en- /!
ployment Of sunlight Small pieces of pol !
ished tin, speculun metal, silyered copper, /
or looking glass, are so fixed ia apparatus,
that the suns rays may be reflected in
line leading to the distant station, where
telescope renders The ray visible. Little
CLEANS Of sunshine have thus been rendered /
visible at distances exceeding bundled
miles.
Sea signals are being improved almost as
decidedly as land signals. 4 simple and
handy system Of dash snd-dot fash signals,
for use al night when flags cannot be seen,
has been introduced into the navy. The /
electric light, the lime light, and peculiar
lamp which burns petroleum vapor melted !
By a kind of blowpipe, all have been tried, I
and all are available under diverse eircum
stances. as well as Argani and other lamps
The principle Is to give long flashes and /
short flashes, the light being visible for a I
greater OF less number Of seconds at time. /
Various modes of applying Opaque screens
and other temporary obstacles have been /
adopted to regulate the alterations of long /
and short flashes; but, when once adjusted. !
and properly worked, the long and short /
flashes are translated into nautical words /
and phrases by means Of a dot-and dash I
cookbook Two ships are thus able to
speak with each other at night when /
several miles apart; and an admiral com
manding q feet may be able to signal to /
every point Of the compass at once, by /
using what IS called an al-round" light |
An the Tsar Round