B12 Mr. GroombriJges Transit Circle.— Polar Expedii ion. 



MR. GROOMBRIDGe's TRANSIT CIRCLE. 



Whilst admiring the mechanical skill of" him who con- 

 sti'ucted the Greenwich mural circle, we were much concerned 

 to hear that there were some grounds to suspect the accuracy 

 of another instrument made by the same artist, and generally 

 considei'ed little inferior to the Greenwich circle itself; we allude 

 to the four-feet meridian transit circle, late the property of 

 Mr. Groombridije. On this gentleman's retiring from the 

 duties of an active observer, the instrument was disposed of, 

 liable, however, to an examination on the part of its maker, as 

 to its efficiency or inefficiency; which investigation being con- 

 ducted by Mr. Troughton, in the presence of Mr. Groom- 

 bridge, the late Professor Tralles, and its intended purchaser, 

 gave reason to fear that some alteration in its figure had been 

 sustained. Accordingly, future and more minute examination 

 was deemed necessary ; and at length it was resolved, that 

 comparisons of north polar distances taken on the same nights 

 with it and the Greenwich mural circle should be entered into ; 

 and the results of many weeks' observations proved, that those 

 obtained by Mr. Groombridge with his instrument, were, to 

 use the words of the Astronomer Royal, " as coincident with 

 those procured by the Greenwich mural circle, as those of 

 the Greenwich mural circle were with themselves." Knowing 

 that the reports of the suspected inaccuracy have extended lar 

 and wide, we feel it due to Mr. Trovighton who constructed 

 the instrument, and to Mr. Groombridge who used it, to give 

 publicit}' to the above statement. It is at present in Black- 

 man-street, and is having eight additional microscojies applied 

 by Mr. Troughton ; it will then have six readings to each of 

 its divided circles, so that all error of division will probably be 

 annihilated. We hope ere long to see it actively employed. 



RETURN OF THE EXPEDITION UNDER CAPTAIN PARRY. 



At length the increasing anxiety for the fate of our brave 

 countrymen who have been so long exploring the Polar 

 Seas, has been terminated by their safe return. The Fury 

 and Hecla arrived at Lerwick, in Shetland, on the 10th in- 

 stant, made the northern coast of England on the 16th, and 

 on Saturday, the 18th, the gallant and enterprising Captain 

 Parry reached London. lie and his brave companions have 

 well earned the admiration of their countrymen and of all 

 mankind, although the discovery of the long-sought north- 

 west passage has not yet been the reward of their exertions. 



The outward voyage in 1821 was fair and prosperous. 

 Passing up Hudson's Straits, the navigators kept near the 

 land on their south, and explored the coast towards Re- 

 pulse 



