the Melbourne Great Telescope. 69 



Lunar Atmosphere (?) — Upon the same question of 

 atmosphere in the moon, I note on the same evening : — 



"While observing the dark disc of the moon I saw a star 

 of medium magnitude approaching, so I closely watched its 

 occultation. On reaching the limb at a slightly indented 

 part, it appeared for an instant to flatten itself out along 

 the surface and then suddenly to disappear. I state, of course, 

 the elFect upon my eye for what it is worth, as a single 

 instance. This occultation took place about 3 h. 30 m., 

 sidereal time (26th Dec. 1870), moon pretty low." 



Sirius. — Not knowing when to look for Lassell's com- 

 panion of Sirius, I proceeded to note all the faint stars 

 which I saw in its vicinity, very difficult to make out owing 

 to the excessive brilliancy of this star in so large a telescope, 

 and on the 9 th Dec, 1870, after a series of micrometer 

 measures of the faint star now called d, I note as follows : — 

 " Calling distance between *S^ and d ^ 10 parts, * 

 20 mag., 15 parts dist. from S, and making angle of 5° 

 preceding line joining S and d, referred to d. Another * 

 20 mag. 45° following same line, 4 parts dist. from d, very 

 difficult, with 6th power (881), definition indifferent." Two 

 months afterwards, in looking over some miscellaneous 

 observations of Lassell's, I fell upon the one relating to his 

 discovery which, with your permission, I will now supply : 

 it is at page 38 of vol. 86, Mems. R. Astronomical Society, 

 and it is as follows : — 



" 1865, Jan. 13. The Comes strikingly plain ; angle of 

 position 76°"67 by 6 measures, with power 678. While 

 trying to measure the distance, the images became greatly 

 confused, and I had in consequence to give up observation. 

 Mr. Marth afterwards endeavoured, on some abatement of 

 the disturbance, to obtain some measures of distance, but 

 without success. The remaining observations relating to 

 this object are entirely by him. 



"While trying to get a measure I remarked to my 

 surprise a star nearer to Sirius than the star " d," which I 

 had not seen before. (Mr. Lassell, Prof Struve, and 1 had 

 not perceived last year any star beside Clark's Comes nearer 

 to Sirius than the. star d.) This new star has perhaps half 

 the brightness of d, and is considerably fainter than Clark's 

 Comes. A rough observation with power 405 gave its 

 position 126°-6, and the star d, 164°-6, distance about 2'. 

 The perpendicular line from the new star upon the line of 



