PN 
Miscellanies. 221 
PR; K. & D. 
Perihelion passage, 1845, June 5542, Gr. m.t, June 5:394902, Ber. m. t. 
Long. of perihelion, 263° 40! 265° ~=3! 53/2 m. equin. 
*« asc, node, 339° 52! 341° 16/ eng June 8. 
Inclination, 49° 0! 49° 37! 4u 
Perihelion distance, 0-4002 0:397809 
Motion, Retrograde. Retrograde. 
18. The Earl of Rosse’s Leviathan Telescope.—In Vol. xiv1, p. 208 
of this Journal, we gave a condensed account of Lord Rosse’s great re- 
flecting telescope, from papers furnished by our friend, Mr. John Tay- 
lor of Liverpool. From the same gentleman we derive the means* of 
making the following statement on the authority of Sir James South, of 
the Royal Observatory, Kensington. 
Last September, Sir James announced, through the Times, that the 
great telescope had been directed to the heavens and with the happiest 
results. The great speculum, however, had then been only approxi- 
mately polished, and was ascertained to possess very nearly the proper 
focal distance. Having been taken out and reground and polished, it 
was (March 4, 1845) reinstated in the tube. Although in our former 
‘notice we gave some important particulars regarding this instrument, 
we now insert Sir James South’s description entire, although at the risk 
of some repetition. 
Description.—* The diameter of the large speculum is six feet, its 
thickness five inches and a half, its weight three tons and three quar- 
ters, and its composition 126 parts of copper to 574 parts of tin; its 
focal length is 54 feet—the tube is of deal; its lower part, that in . 
which the speculum is placed, is a cube of eight feet; the circular part 
of the tube is, at its centre, seven feet and a half in diameter, and its 
extremities six feet anda half. The telescope lies between two stone 
walls, about 71 feet from north to south, about 50 feet high, and about 
23 feet asunder. These walls are, as nearly as possible, parallel with 
the meridian. 
“Tn the interior face of the eastern wall a very strong iron arc, of 
about 43 feet radius, is firmly fixed, provided, however, with adjust- 
ments, whereby its surface facing the telescope may be set very 
accurately in the plane of the meridian—a matter of the greatest im- 
portance, seeing that by the contact with it of rollers attached to one 
extremity of a quadrangular bar, which slides through a metal box fixed 
to the under part of the telescope tube, a few feet from the object end of 
the latter, whilst its other extremity remains free, the position of the 
telescope in the meridian is secured, or any deviation from it easily de- 
termined, for on this bar lines are drawn, the interval between any ad- 
* From the Times, and the Illustrated London News. 
