New-York daily tribune. [volume] (New-York [N.Y.]) 1842-1866, 1861-05-31
THE CALCIUM LIGHT.

To ne Edibv " TAs ~ Y. TriSss< nr
Sra: observe article in your paper Of Nay l6, -
another in your issue Of to-day, stating that Gocsss
ment bad made arrangements forplacing calcium lg1
upon Fortress Monroe for the purpose Of observing ~
movements Of the enemy, guarding against suddsa
night attacks. - well 70 mako the blockade msss
effective" to which is added suggestion that Il -
placed upon other forts and coastguard vessels for
like purpose also, "for night movements In the army.
enabling the recounoeriDg party TO scan the country
at long distance In advance, bringing the enemv q
full view, while those who use It. being the blind
side would be eec ually screened from observation"
Having made Of the calcium light Tor the aa u
years. and constructed is apparatus for various p1y-
poes will you allow me, through your ya'uaees
biiy of this light for the above porpo.es The cs!a
um Fight, also called the Drummond hght-it having
been u-ed BY Prot Drummond In bis cosst survey q
ireland--s produced by throwing jet Of the con-
biaed gsses, oxygen And hydrogen upon small Pdess
Of gnslsked tuio with the compound blow.piPs. -
which the lime Tor lime bslD 10 heated to high dats
Of incandesenre producing thereby an intense bsi
light.
To concentrate thi. Heh. upon any gwen point. .
ne to throw the rays forward in nearly parallel ipsa
Now, in order to render this light Of soy avsilsbls
use to Fortress Monroe, or coxtyuard vessel, it ma
be sufficiently powerful 70 bring the enemy 10 fl
the range Of naed cannon or Dahlgren guns TIL
cannot Be done, even with pressure upon The gsasso
oqusl to 800 pounds TO the square inch. have usaa
with this pressure Nor yet with The most power.
full electric light produced for this reason, anoeg
many Others that psrsbols cannot be manufactured
with sufficient accuracy III shape and perfection a
posh of surface, to concentrate the required amoa0
Of ray upon any given point ut that distance. HeDc
there can be no foundation for the statement pot fe
In your paper Of May l6, that the calcium hg1A
placed upon the Ldtaing Observatory in this ciY
cast q distinct shadow Vt Tarrytown, thirty milo
dist Ant.'
The calcium light, sometimes used upon Bsrnumg
Museum powerful one with reflector Ia psrabelat
be ind il, and, though not powerful can ne Coz.
structed yet the movements Of e0emy c0I not -
die incty by il a. far ~ Grace Church
deny, then, that the calian light DO made Of -
10 the extent for the purpos~s dicated.
TN The other hand, it would be most dangerous az
pertinent II will be remembered that Prof. Drum
u.ond made use If this light, sn extraordinarily
vivid si. hting point, lhe used it without rcAece
which renders its appearance distance ike that q
an intensely brilliant starr On account Of its c0nc0-
trated brillsncy.
Thus il will be seen that this light whether PLACED
upo fortress vessel. would BE- most perfect to,
at for the enemy, while their sition, at any O..
siderable distance, could be sscertAined except ~
the fash Of their cannon. r. sr
Ills subject should not be slightly mooted o. su-
peril Tally toyed with; it be made dsngeroos
playibiug and no hazardous experiments should On
tert.neo ~ the Government, unless the subject hD
been previously and ade luately tested.
Noe lis asd lit Wet TVeatsi,d street. " May n, isl