PHOTOGRAPHIC REVELATIONS.
The remarkable successes of astronomical photography, which depended
upon the plate's power of accumulation of a very feeble light acting
continuously through an exposure of several hours, were worthy to be
regarded as a new revelation. The first chapter opened when, in 1880,
Dr. Henry Draper obtained a picture of the nebula of Orion; but a more
important advance was made in 1883, when Dr. Common, by his
photographs, brought to our knowledge details and extensions of this
nebula hitherto unknown. A further disclosure took place in 1885, when
the Brothers Henry showed for the first time in great detail the
spiral nebulosity issuing from the bright star Maia of the Pleiades,
and shortly afterward nebulous streams about the other stars of this
group. In 1886 Mr. Roberts, by means of a photograph to which three
hours' exposure had been given, showed the whole background of this
group to be nebulous.
In the following year Mr. Roberts more than doubled for us the great
extension of the nebular region which surrounds the trapezium in the
constellation of Orion. By his photographs of the great nebula in
Andromeda, he had shown the true significance of the dark canals which
had been seen by the eye.
Pages:
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164