Telescopes — Life of Fraunhofer. 303 



I hope to see a specimen of Lerebours' telescopes, as a 

 person belonging to Salem, has, by my advice, sent out for 

 one that will cost two hundred dollars ; this is the price of a 

 small instrument, but still it will show the skill of the artist. 

 An eminent philosopher in Great Britain, in a letter to me, 

 remarks, that the continental achromatic telescopes surpass 

 them all ; [the different telescopes lately made in England,] 

 and he rebukes the negligence of the British government. 

 I wrote to Europe, with the special view of obtaining infor- 

 mation which might be useful to all our scientific institutions. 

 But it was so long before it arrived, that I do not wonder 

 your college should have engaged an English artist; although 

 I am now sorry for it. You have, sir, no doubt, read the 

 beautiful memoir of the life of Fraunhofer, published in 

 Brewster's Journal, 1827, page 1. How feelingly the wri- 

 ter expresses himself on the death of this truly great and 

 eminent artist and philosopher, and how indignant he seems 

 to be at the neglect of the English government to Dollond, 

 the inventor of the achromatic telescope. 



Permit me sir, to inquire of you, if you have repeated the 

 experiments of the French chemists on the making of dia- 

 monds ?* It is a very remarkable circumstance that the dia- 

 mond, should unite a very high refractive with a low disper- 

 sive power. I do not recollect any other instance of it. 



Rapport du Jury Central Exposition, 1 823. 



M. Lerebours, opticien, a Paris, place du Pont-Neuf, qui 

 requt en 1819 une medaille d'or, a expose plusieurs instru- 

 ments d'optique qui sont tons tres dignes de la reputation 

 dont il jouit dans le monde savant. Deux de ses lunettes, 

 dont une a neuf pouces et demi d'ouverture, ont fixe I'at- 

 tention du jury. Rien de plus parfait n'est certainement 

 sorti des ateliers d'aucun opticien. 



Le jury decerne une nouvelle medaille d'or a M. Lerebours. 



* The materials mentioned by the French chemists, namely, sulphuret of 

 carhon and phosphorus, were placed in contact as soon as the facts were an- 

 nounced, in February, but, as it requires the greater part of a year to produce 

 the result, it cannot be expected as yet. It is said that the phosphorus oper- 

 ates by detaching the sulphur from the sulphuret of carbon, and that thus the 

 carbon is gradually made to crystallize, so as to produce diamond, in small 

 masses, but transparent and hard, so that the Paris jewellers have pronounced 

 them to be identical with the natural diamonds. — Editor. 



Since this note was written, we observe that this reputed discovery is dis- 

 puted by some of the most eminent of the French chemists. 



