Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1894-09-11
SECRETS OF STARS.
low the Camera Is Made to Reveal The
Wonders Of The Heavens.
CELESTIAL TOPOGRAPHY
Remarkable Progress I'm Astronomical
science Due 20 the Use Of the Scnsi-
dive riaie.-Facts and Theories.

sultory manner. the progress OF science
is aware that In the Department Of As
tronomy at the present time one OF the
great levers used for prying into natures
secrets Is photography. The great ad-
vance which astronomy has made in re-
cent years. particularly In the past de-
oade. IS due. not so much 10 the superior
telescopes with which astronomers are
now equipped. as TO the employment Of a
new method OF using the telescope Itself.
u is as a camera. either with or without
srccirogcopc attached; that the tele-
scope IS now used the most effectively.
II has been found that in observations OF
certain kinds: for instance. the study Of
star-spcctfa and nebulae--not only Is a
great saving Of labor and time effected
by taking an impression OF the object on
a scnsitizcd plate. and studying It at
leisure. but that such a plate can nc
tuauy be made 10 reveal more than can
De seen in direct observation with the
eye. Celestial photography has not been
brought 10 This degree Of nicely without
a deal Of experimenting. and before
giving some account OF the various uses
10 which 70 IS now put. IL may be well
T. devote = few paragraphs 20 its history.
Tho FIST celestial object 90 be photo
Craphcl was the moon. II Is a compare
lively easy object ana was especially
suited 20 tho early experiments. since It's
lleht does not need 10 be toned down.
g. does that OF the sun. the next object
u De- attacked successfully. AS the art
nf photography was improved. lunar pho
roEraphs of greater and greater excel
lcucc were obtained. and they are to-day
The most intcrcsling popularity, OF all
photographs II the heavenly bodies, and,
g may De- added the most instructive.
Thousands Of persons who have never
ssI the opportunity OF looking through
telescope are familiar with the moons
.Geecopic appearance through these
'.tlm representations Of II. And yet
% n scientific point OF view. the lunar
-h.t0cnphs are perhaps the least valua-
bio of any ON the astronomers list. The
pest photograph Of the moon does not
.ual IN the matter Of minute detail n
t.w which can be obtained by direct
tyr observation.
PHOTOGRAPHS OF THE sun.
With the sun the case IS the rev rse.
Photographs OF The sun being taken in
rt. miuutest fraction Of second OF
time. have all the advantages OF an in
..liaucous Photograph Of an object in |
r..Hn. The earths atmosphere Is al /
v.vs iu I'll state or unrest. caused by /
currents OF air Of different temperatures. |
Particularly SIS 20 unsteady in the day |
f..e when subjected directly 70 the |
suns rays. As consequence. when the /
sun is examined with u telescope the !
cutir. outline az its disc ana whatever /
spots there may bee upon IL are continu- |
ally waving and boiling" as IF seen /
across a. bonfire. only at intervals can /
,ne catch m1mentary elimp-es Of the !
iuer details 81 the object DE is trying !
To- make out Professor Langley, whose /
.u- drawings ~ sGu-spOtS are the admi- z
-auuu of al astronomers has affirmed /
is his own experience that one may /
deem himself fuftluatr IT, after having |
t.pt has telescope steadily ON the sun !
Turing the entire day he has been re- /
varied with five minutes in all o., really !
distinct vision.
Th. instantaneous Photograph reduces |
IBIS difficulty 10 a minimum. If the in /
s'1Nt # the exposure Of the plate hap /
pens 90 ." favorable. I'm that single in |
.fuIt mass of details Of the solar sur |
'a.' 81 Impressed indelibly on the plate. |
sh.rh. though hey might be "glmpsed." !
T0.'i ie lost before being fairly caught
.r fla eye and could be depicted with
H.fr'r When Il is considered that the
"details II the suns surface, unlike
chose Of the moOn's. are continually /
changing, and that when one has failed |
90 catch a particular combination Of de- /
tails. f. is gone forever the value OF |
photography for depicting the suns sur !
face. ana particularly for securing the |
ever changing features Of the suns dark /
spots can be appreciated The splendid /
Hf. ~ Of al. 4
scu have given astronomers. probably a
clearer idea OF the characteristics Of its |
ihotosphere than they could ever have |
gained by direct obs rvation Of the sun
itself
EARLIEST CELESTIAL PICTURES.
Celestial photography is usually con-
Fdercd 10 have begun with the expert
uonts Of Bond and Whipplc, made at the
Harvard College Observatory. about the
year 1850, although ten years earlier than
his Or. j. W Draper, Of New York. had |
occurred a small daguerreotype picture Of
h" moon, ana Foucault, Of Paris, a few
years later successfully daguerreotyped
.Ne sun.
The most distinguished Of those who
Immediately followed Bond in this new
.ril are Mr Warren de Ia Rue in Eng
and. and In America. Mr.. Louis NJ
tu,hccfurd and Professor Henry Draper
both Of New York. 1t was mainly
through the skill and devotion Of these
amateur cXperimenters. working with their
Own means. and with instruments of
th.ir own make that lunar and solar
Photography were brought 10 the advanced
ice limited at above. Some Of the photo
graphs OF the moon. taken In those early
Jays. are magnificent pictures, three or
m.r" feet I'm diameter, and for excellence
f definition have hardly yet been sur
PASSED.
The attempt 20 Photograph the stars was
ir long time only partially success
OIL. The light of the stars. with the eX-
r'ion OF the very brightest, proved too
Z .-h.e % make more than an uncertain
IMPRESSION on the wet plates used in
D." GA collOdian process, with any practi- ,
able length Of EXPOSURE and there were.
besides. instrumental difficulties, which
were removed only after long and patient
experimenting. About the year 1854 how
ever Mr.. Rutherford. having found the
ordinary r,fracting telescope quite I'M
llitei 20 photography conceived the idea
- making a lens specially corrected for
Doe chemical rays Of light. and which
s.lil. therefore. be unsuited for ordinary
purposes. Such a lens. nine inches in
diameter. he ground and polished with his
1Wn hands. With this lens he not only
occurred much finer pictures of the moon
.tln he had been able to obtain before
as largest pictures had been only five
inches in dlamcter-but he was also fairly
1cc~ssful with the stars. Photographs
Of tte Hleades. and other star-clustcrs,
aiken by him at this time. showed stars
faint as Of the ninth magnitude, and
&c. the first really at all satisfactory
ircimcns OF stellar photography. Mr.. /
.ltherlurd subsequently discovered that
c-uiis nearly as good could be obtained
sin an ordinary telescope. by placing in |
rort Of us composite-Objcct-g Il third
ls. which should shorten It's focal
'ngth about one tenth. This is the
Photographic lens" now provided for
most large cquatOriais. enabling them 10
D" used either for eye-observations, or for
photography.
OF THE DRY PLATE.
in 1871 an important advance was made
~ The art Of photography by the introduce
ton OF the dry plate" This great i'm
.f0ycmcnt which rendered instantaneous
photography possible with terrestrial OBJ
,.cts and opened the field OF photography
wide TO amateurs" gave d new Impulse
10 crlestia! Photography az well. The
new plates were not only more sensitive
than the old but. matter Of hardly
less Importance. there was no limit to the
!ne during which they might he exposed.