The New York herald., 1850-08-06

ASTRONOMICAL DAGUERREorYPINa. Bond,
OF the Cambridge Observatory, in a communication
to the Boston ADVERTISER of the I'd inst, upon tho
SUBJECT of daguerreotyping stars, of which he has
made an experiment upon the star Lyr1, which il
hot visible 10 the naked eye, says.-The question
Will doubtless occur TO many of the iders of that
article, 10 what good purpose this discovery be
applied? One of the first direct apple atoms of it
would be the measurement of the angles of opposi-
ton and distance of double stars lis interesting
to be assured OF the fact, that the light emanatiug
from the stars possesses the requisite chemical
properties to produce effects similar to certain of
the solar rays, and that these properties retain their
efficacy after traversing the vast distance which
separates us from the stellar regions. OF this dis
tance some idea may possibly be formed, if we can
imagine plane of two hundred millions of miles
IN extent, at the distance of the alpha Lyrw.
and favoraby presented to a spectator situated on
the earth, apearng as a mere point only measura-
Bile by the and OF an excellent telescope, furnished
tor an accurate mcrometer or that light moving
al the rate Of 100 900 miles in a second of time,
would require more then twenty years to traverse
the intervening space. Yet such the facts, and
i follows that the ray Of light which made the
first impression our daguerreotype plate ON
Tuesday evening, took its departure from the star
n more 'had nan swsny years ago, Long Goore Ia
Our experiments have also a bearing upon the ma
ture Of the light emitted from the stars The images
which we have thus far obtained, are quite decided,
having pretty distinct nuclei, although elongated,
and too broad for the nicer purpose OF measure
ment. This apparent enlargement of the disc
attribute, in great measure, TO two causes. One
il the variable nature Of atmospheric refraction,
when influenced by sudden changes of temperature.
This trouble we hope 10 get rid Of by ncre asing the
sensitiycness Of The surface receiving the impress
sion. The other operation will then require less
time, and, Of consequence be subject TO fewer and
less extensive vibrations. The other difficulty to
be overcome is the irregular motion Of the ma
chneTy which carries the telescope. Althou gh the
machinery at present attached TO the telescope is
the best that German ingenuity could devise, and
answers tolerably good purpose ON orlin,ry occa-
slons, yet II IL deficient for our nicer operations
The telescope should, during the nicer process be
prope He'd with uniform sdereai motion in order
that the successive rays from the star may fall on
precisely the same part Of the plate which Is 10 re-
ceive the impression. IL this be no; the case the
image will be deficient in dstinctness of outline
and unduly enlarged. To effect this we intend to
apply to our great equatorial machine which we
have devised for the purpose Of producing Uniform
rotary motion, one Of which machines is now con-
sructing at the observatory, to be used in connec-
ton with the electrographic operations Of the Coast
survey IL is our purpose TO pursue the subject Of
daeuerreoyp.ne the stars, proceeding step by step
from the brighter to those Of lesser magnitude. We
do not despair Of Obtaining ultimately faithful pic
tures OF clusters OF stars, and even nebule.