{"character_count": 1778, "word_count": 309, "ccnet_language_score": [0.8963000178337097], "ccnet_perplexity": [970.2999877929688], "fasttext_language": ["en"]}
Improvement in tie Telescope A combina-
tion Of the telescope with the daguerreotype has
recently been effected in its application to astro


nomical purposes, by the Royal Society of Bohe-
mia. Professor Doppler says, that notwthstand-
ing the extreme susceptibility of the human eye, it
is surpassed many thousand times by an iodizcd
Muller and Weber have shown that the diameter
of one of the pupl@ of the retina is no more than


the 10000 of and inch. But comparing the sus-
ceptibilhy Of the retina pupila with microscopic
experiments made with Diguerre's plates, a sin
gle globule of mercury only becomrs visible by
and 800 fold magnifying power microscope. and
on the space Of daguerre plate equal to one reti-
"a pupil@, more than 10000 minute globes of
mercury are to be met with Each of these is
capable Of producing the image of well-de6ned OBJ
jects Thence Professor Doppler argues that
Daguerre's plates are 10000 times more suscepti-
bic of impressions than the human eye. At the
exact point threfore, when the image of celestial
body is formed before the object lens of telescope
Of considerable length all apparatus is to be place
ed where silver iodizcd plate can be securely
inserted. AS the place of the image is the same
for all celestial objects, a plate Of well-de6ned
constant thickness can be inserted with great ac-
curacy., In this way images of the smallest fixed
stars can be obtained, if the light will be sufficient
to affect the plates. As these images will have
been magnifrd Through the action of an object
lens, say of 10 inches focal lengthy TO the extent
of IA times their natural appearance, and again
magnifed 1900 fold, the angle Of vision under
which they are now to be viewed will have been
increased 5000 fold. r-:..... ~. ,ta.9r .. q.