Astronomical News. • 259 



Lad been executed some years before — the bridge of Colebrook- 

 Dale, thrown over the Severn. It consisted of a single arch of 

 100 feet span, and was constructed about the year 1779. It wiis 

 built entirely of cast iron, and the commission state that at the 

 time at which they wrote, it seemed to have suffered nothing 



It should be 



use 



added that at the same session, when this report was presented, 

 a locksmith of PariSj named Clement, brought forward plans for 

 different parts of an iron bridge, which he proposed to build. 



The last paragraph of this Eeport is interesting, as it shows 

 the state of the iron industry in 1787. ^^ We conclude, in view 

 of all that has been exhibited, that the construction is shnplc 

 and solid, and fitted to resist the weight and wear to which it 

 will be exposed, and that it deserves to be tried : and finally^ 

 that it will furnish an example of the application of a nietal 

 which has not been enough used on a great scale, 

 many occasions it has been employed with success." 



Could the savants Bossut, Borda and Eochon return to the 

 world they would see their views fully realized. 



Astronomical News. — The prize established by Lalande for as- 

 tronomical discovery, has been divided this year between Messrs. 

 Chacornac, Goldschmidt, and Pogson of Oxford ; the first for his 

 discovery of two planets, Leda and Letitia, on the 12th of Jan- 

 uary and 8th of February, 1856 ; to the second for the discovery 

 of itarmonia and Daphne, the 31st of March and 22d of May^ 

 1856 ; and to the last for the discovery of the planet Isis, the 

 42d of the asteroids ; the first four of these were earliest seen at 

 Paris, the last at Oxford in England. 



When Sir John Herschel was at the Cape of Good Hope, he 

 was much troubled by his speculum ; it tarnLshed constantly, and 

 after five or six days was unfit for service. The same difficulty 



IS encountered in all observatories. In 



take 



ject, and he has proposed as an improvement, that, for the metallic 

 speculum, one should be substituted made of glass well polished 



after 



means 



oil. When taken from the bath, the_ coating of silver is dull, 

 but it is readily polished by friction with a skin covered with a 

 little English red: it acqnircs, in a few moments, a brilliant lus- 

 tre and gives fine reflections. 



Although we cannot affirm that the lustre of this new specu- 

 lum will be of long duration, there is at least reason to hope well 

 of it, since silver is less alterable than copper and bronze ; but 

 even if it becomes dull it is as easily polished us at first. 



Ek 



CLcr 



In consequence of a terrible gale, the two submarine cables 



