"Lacaille seems to have been the first
person ever to observe systematically the whole sky" -- D S Evans |
Evans (1990) notes: "Considering that this list is based
on the data from [the star catalogue], that is, almost always one shot of the
passing sky in a very small telescope, certainly very inferior to modern
binoculars, it is as good as might be expected. One can also reflect that
Lacaille seems to have been the first person ever to observe systematically the
whole sky, an honor which the present author once ascribed to Sir John Herschel,
who used much the same technique with a telescope of some ten times larger
diameter from a site some 6 miles south of Lacaille's. He, of course, did very
much better and is the principal source of the southern data in the NGC."
LACAILLE ALSO STUDIED
the Magellanic Clouds: "As a result of examining several
times with a telescope . . . those parts of the Milky Way where the whiteness is
most remarkable and comparing them with the two clouds common called the
Magellanic Clouds, which the Dutch and Danes call the Cape Clouds, I saw that
the white parts of the sky were similar in nature, or that the clouds are
detached parts of the Milky Way, which itself is often made of separated bits.
It is not certain that the whiteness of these parts is caused, according to
received wisdom, by clusters of faint stars more closely packed than in other
parts of the sky, whether of the Milky Way or of the Clouds, I never saw with
the ... telescope anything but a whiteness of the sky and no more stars than
elsewhere where the sky is dark. I think I may speculate that the nebulosities
of the first kind are nothing more than bits of the Milky Way spread round the
sky, and that those of the third kind are stars, which by accident are in front
of luminous patches." (Quoted from Evans)
"One can add among the phenomena which strike the eye of
anyone looking at the southern sky, a space of about 3 degrees in every
direction which seems intensely black in the eastern part of the Southern Cross.
This is caused by the contrast with the brightness of the Milky Way which
surrounds this space on all sides." |