The republic. [volume] (Washington [D.C.]) 1849-1853, 1850-08-12
Dnguerreotyping Stnr..

III was recently announced tilat Nlr Bono, oil the
Cambridge observatory, had succeeded in taking
daguerreotype OF the star Lyr@, which is not
visible to the naked eye. An Interesting commu-
nication in relation TO this subject, from Mr.. Bond
is published in the Boston dduertiser, from which
we make the following extract:
"The question will doubtless occur TO many of
the readers OF that article, 10 what good purpose
can this discovery be applied? One of the first di
rect applications of II would be the measurement Of
the angles OF opposition and distance of double
stars 1t is interesting to be assured of the fact,
that the light emanating from the stars possesses
the requisite chemical properties 10 produce effects
similar to certain of the solar rays. and that these
properties retain their efficacy alter traversng the
vast distance which separates from the stellar
regions OF this distance some idea may possibly
be formed if we can imagine plain of two hun
dred millions of miles in extent, Mt the distance
OF the star Alpha LyrS, and favorably presented
to a spectator situated on the earth, appearing
mere point, only measurable by the aid
of excellent telescope, furnished for sccu-
rate micrometer: or that light moving at the rate
OF 10000 miles In a second OF time would require
more than twenty years 10 traverse the intervening
space. Yet such are the facts, and it follows thai
the ray Of light which made the first impression
our daguerreotype plate on Tuesday evening, took
its departure from the star more than twenty yean
ago, long before Daguerrc had conceived his admi-
/ rable invention.
"Our experiments have also a bearing upon the
nature of the light emitted from the stars.
"The images which we have thus far obtained
are quite decided, having pretty distinct nuclei al
thoug gh elongated, and too broad for the nicer
purpose of measurement. This apparent enlarge.
ment OF the disc We attribute, in great measure,
TO two causes. One is tie variable nature of atmo-
spheric reiraction, when influenced by sudden
changes OF temperature. This trouble we hope to
get rad Of by increasing the sensitvcness Of the
surface receiving the impressions. The o,her ope-
ration will then require less time, and, of consc-
quence, be subject 10 fewer and less extensive vi
brations.
IT ne other diff ulty be overcome irregular
motion OF the machinery which carries the telescOpc
Although the machinery al present attached 10 the
telescope Is tho best that German ingenuity could
devise, and answers tolcrably good purpose on
ordinary occaslons, yet 1t IL deficient for nicer
operations. The telescope should during the nicer
process, be propelled with uni iorm siderea notion
IN order that the successive rays from the star may
fall on precisely the part % the plate which is
to receive the impression. II this be not the case
the uage will be deficient IN distinctness og out.
| line, and unduly enlarged,
"To effect this, We intend 10 apply TO our great
equatorial machine which we have devised for the
purpose of producing uniform rotary motion, one
VI which machines - now constructing ~ tic Oh.
scrvatory, 90 be used in connesion with the cleo
trographiC operations Of 10 coast survey.
"ltis ou- p-rpose to pursue the subject Of daguer
reotyping the stars, proceeding step by stcp from
the brighter 10 those Of lesser magnitude We do
not despair Of Obtaining ultimately faithful pictures
OF clusters O! stars, and even nCbulR.
"Mr. Whipple, the dagucrreotypist, and his as
sistants, have chccriully aud pcrseycringly lent
their aid on several occasions during the past aud
present years furnishing us plates, apparatus and
valuable time, without charge, -