Nature July 18th 1872
The Melbourne Argus states that valuable work is being
performed with the great telescope at the Melbourne Observatory.
At a recent meeting of the Royal society, Mr Ellery, the
Government Astronomer, stated that some photographs of the Moon had been
obtained better than any he had any knowledge of.
The picture of the Moon taken in the telescope was about three inches in diameter, while the primary pictures of the photographs of the Moon hitherto made public by Mr De La Rue were only three quarters or even seven eighths of an inch in diameter, though subsequently enlarged to something like two feet.
Nature July 25th 1872
The Melbourne Telescope
Mr Ellery has been so good as to send me an enlargement of
the lunar photograph taken with the great Melbourne telescope. This picture, Mr
Ellery tells me was taken on the second evening trial; it is very beautiful,
although not so critically sharp as I have obtained with my Newtonian
equatorial of 13 inches aperture, and a little more than 10 feet focal length.
This sharpness, however, is a mere question of the shadiness
of the atmosphere; and I feel persuaded that pictures will be taken with the
Melbourne telescope far surpassing any hitherto procured.
In my telescope the focal length varies from 1 inch to 1 and
two eights inch in diameter, according to the distance of the Moon from the
earth.
The primary picture of the Melbourne telescope (an
enlargement has been sent to me) is 3 and 3 sixteenths in diameter; hence the
structure of the collodion and minute defects in it are of much less importance
then when smaller instruments are used.
The employment of the great Melbourne telescope for astronomical photography cannot fail to be of great advantage to astronomy, and I should be very glad to see a similar instrument t work in England, notwithstanding its much-abused climate.
Warren De La Rue
www.theramblingastronomer.co.uk
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