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faint idea of the overwhelming pressure which the last three 

 years exerted here on all who were resolved to discharge the 

 duties which men owe to their country. Lord Rosse is not a 

 person to seek knowledge or enjoyment in the heavens, when 

 he ought to be employed on earth ; and he devoted all his 

 energy to relieve the present misery and provide for the future. 

 During this interval some parts of the machinery which could 

 be finished by his workmen without his superintendence, were 

 completed ; a duplicate speculum, which had been previously 

 cast, was ground and polished by them ; but nothing of note 

 was performed except the discovery of the spiral arrangement 

 in 51 Messier, and the resolution of the great nebula of 

 Orion, both which have been published by Dr. Nichol. 



These days of evil are past ; and though the future is still 

 dark and threatening, yet he trusted it would bring nothing 

 but what wisdom and benevolence might turn to good ; and in 

 this same hope Lord Rosse felt himself at liberty to resume 

 his favourite pursuits. Dr. Robinson found the new speculum 

 imperfectly polished, and the old one tarnished by wet, which 

 had found access to it while it was not attended to. No diffi- 

 culty was apprehended in repolishing; but for a long time the 

 process failed unaccountably. The figure was hyperbolic, 

 and the surface irregular. This last can be easily ascertained 

 during the operation. For the first two hours, the peroxide 

 of iron used as the polishing material covers the surface with 

 scratches, which gradually disappear afterwards. If these be 

 examined by the reflected image of a lamp or window, when 

 the work proceeds well they appear as dark lines, otherwise 

 they show a luminous edge indicating a curvature of the ad- 

 jacent surface ; and whenever this occurs, the definition will 

 prove imperfect. Weary at last of these trials (each of which 

 involved four days of hard work), Lord Rosse determined to 

 experiment on one of the three-feet specula, which, as Dr. 

 Robinson formerly explained to the Academy, could be exa- 

 mined on the engine, by a dial placed above the tower where 



