38a M. Gmnandh Flint Glass. 



two thousand years ago,) and that the actual loss of hest ui 

 that period has not produced a variation in the length of the 

 daj'^, of the two-hundredth part of a centesimal second. 



Land. Phlos. Mag, and Journ, 1824i 



15. Zoology.' — Baron Cuvier is said to be engaged in pre^ 

 paring for the press a great general work on Ichthyology. 



16. Fine Arts. — Mt- Milbert, a French gentleman who 

 has resided several years in the United States, as a naturalist 

 in the employment of the French government, is about to 

 publish in Paris his '"Voyage Pitioresque dans I'Etat de 

 New- York." We had the pleasure of examiniiig his port- 

 folio some years since, while he was in this country ; and 

 from the specimens there exhibited, we be ieve that this wiiS 

 not be excelled even by his celebrated Travels in the Isle of 

 France, a work of a similar nature. t). 



17. M. Cruinand^s Flint Glass.* — Opticians and astrono-* 

 mers have long lamented the imperfection of refracting tele- 

 seopesj from the impossibility of obtaining flint glass for lenses 

 perfectly homogeneous, v7ithout stnae, or any other defects, 

 and of sufficient sise. These difficulties are at length re-* 

 removed by the invention of M. Guinand, an ingenious, 

 self-taught artist, of Brenets, in the Canton of Neufchatel, in 

 Switzei-land. This man in his youth assisted his father ns 

 joiner, and at the age of thirteen became a cabinetmaker. 

 Havingseen an English reflecting telescope, he procured leave 

 to take it to pieces and put it together again. This gave the 

 first impulse to that object, which afterwards gave him so 

 much celebrity. When he attempted to manufacture achro- 

 matic glasses, meeting the same diffii:ulties which others had 

 experienced, he began (at the age of 35) to make experi- 

 ments on the manufacture of glass. With no advantages, 

 except those which his own ingenuity supplied, he 

 erected a furnace, with his own hands, and continued 

 for many years a series of expensive and fruitless experi- 

 ments, labouring occasionally at some mechanical employ- 

 ment to earn the means of subsistence, and of purchasing 

 woodi, and the necessary materials for his furnace, his cruci- 

 feles, and his glass. He carefully noted the particulars of 



^ Abstract of a Tract of 25 pages, 8vo. Loadon 1825, 



