tne ee ele 
Miscellanies. 223 
Perfection of figure in a telescope, must be tested, not by nebule, 
but its performance on a star of the first magnitude. 
“Tf it will, under high power, show the star round and free from 
optical appendages,” it will not only show the nebulz well, but any 
celestial object as it ought to be. ‘* Regulus on the 11th, being near the 
meridian, | placed the six feet telescope on it, and with the entire aper- 
ture and a magnifying power of 800, I saw (says Sir James) with in- 
expressible delight, the star free from wings, tail or optical appendages ; 
not indeed a planetary disk, but as a round image resembling voltaic 
light between charcoal points; the telescope, although in the open air, 
and the wind blowing rather fresh, was firm as a rock.” 
_ On subsequent nights, observations of other nebule, amounting to 
some thirty or more, removed most of them from the list of nebule, 
where they had long figured, to that of clusters; whilst some of these lat- 
ter, but more especially 5 Messier, exhibited a sidereal picture in the tel- 
escope such as man before had never seen, and which for its magnifi- 
cence bafiles all description. 
** Of the moon a few words must suffice. Its appearance in my 
large achromatic, of twelve inches aperture, is known to hundreds of 
your readers ; let them imagine that with it they look at the moon, whilst 
with Lord Rosse’s six feet they look ino it, and they will not form a very 
erroneous opinion of the performance of the great telescope. 
“On the 15th of March, when the moon was seven days and a half 
old, I never saw her unillumined disk so beautifully nor her mountains 
so temptingly measurable. On my first looking into the telescope, a 
star of about the seventh magnitude was some minutes of a degree dis- 
tant from the moon’s dark limb. Seeing that its occultation by the moon 
was inevitable, as it was the first occultation which had been observed 
with that telescope, I was anxious that it should be observed by its noble 
maker; and very much do I regret that through kindness towards me 
he would not accede to my wish ; for the star, instead of disappearing 
the moment the moon’s edge came in contact with it, apparently glided 
on the moon’s dark face, as if it had been seen through a transparent 
moon, or as if the star were between me and the moon. It remained 
on the moon’s disk nearly two seconds of time, and then instantly dis- 
appeared, at 10h. 9m. 59°72s. sidereal time. I have seen this apparent 
projection of a star on the moon’s face several times, but from the great 
brilliancy of the star this was the most beautiful leversaw. The cause 
of this phenomenon is involved in impenetrable mystery.” 
Sir James South describes the Newtonian telescope and the improve- 
ment of Le Maire, as follows. 
“Thus, then, the difficulty of constructing a Newtonian telescope of 
dimensions never before contemplated is completely overcome ; but to 
