74- Royal Astronomical Society, 



from his former connexion with the Mint as assistant-engineer, had 

 great facilities for procuring the hest assistance which the country 

 afforded, he undertook the re-erection of the instrument, which, his 

 own services being gratuitous, would not exceed 300 rupees. This 

 offer being communicated to the governor, the sum specified was 

 readily advanced. 



The stone pillars are two feet square : the upper part of one had 

 been greatly split and shaken by unskilful perforations, and Captain 

 Shortrede directed the upper fifteen inches of each to be taken off. 

 These he replaced by two blocks of Puna stone, which are eighteen 

 inches square at bottom, sloping to twelve inches square at top. This 

 size seemed sufficient for steadiness, and was as large as could well 

 be procured at Puna or transported to Bombay. Due care was taken 

 to attach the blocks perfectly to the piers. 



The new Y plates were of bell-metal, cast at the Mint, and well 

 and truly worked ; particular care was taken that the plate bore truly 

 on the stone near the screw-holes. 



The pivots of the axis are supported throughout their length ; 

 the motions for every adjustment were found free and without shake. 

 Instead of the usual Y, Captain Shortrede adopted a collar bearing, 

 which he intended should exactly fit the pivots. The workman, 

 however, made them somewhat large, and, as he finished them by 

 grinding, not quite true. Having no time to get new collars made, 

 Captain Shortrede had a groove cut out at the bottom of the bearing 

 and at the top of the covering-piece, in each of which a slip of wash- 

 leather was secured by lac- varnish. These do not interfere with the 

 bearing, and they stop the dust before it comes to the bearing. The 

 constant daily shower of sand from the sea-breeze and neighbouring- 

 shore would soon destroy any pivot working in the ordinary way ; 

 and this consideration suggested the collar mounting, which was 

 intended to be as close fitting as possible. No iron was used in the 

 work, the liability to rust in such a situation makes the material 

 unsuitable. 



The instrument thus fitted up continues to work satisfactorily. 

 There are no counterpoises, Captain Shortrede (luckily perhaps) not 

 having had time to procure them before quitting Bombay. 



Self-luminous Spot in the Moon. 



On the 11th of December last, at 6 p.m., while Mr. Hodgson, of 

 Fir Grove, Eversley, was observing the dark body of the moon, " a 

 bright spot, about one-fourth the angular diameter of Saturn, was 

 perceived, which, though it varied in intensity like an intermitting 

 light, was at all times visible." On this occasion Mr. H. used an 

 achromatic telescope of five foot focal length, and powers 50 and 

 80. The bright spot was best seen by the higher power, probably, 

 as he suggests, because the field was smaller and darker, but it was 

 instantly visible to the most uninitiated eye when the bright part of 

 the moon was excluded from the field. 



On the following day glimpses of the same spot were caught be- 

 tween passing clouds with a Newtonian reflector ; power 40. 

 ■ From Mr. Hodgson's sketch, the bright spot is about 5' below the 

 real northern point and near the following limb. 



