O. MISCELLANEOUS. 579 



INDEX OF PATENTS FROM 1790 TO 18*73. 



A very important work has just been commenced by the 

 Patent-office, under the title of "Index of Patents for Inven- 

 tions issued by the United States Patent-office from 1790 to 

 IS 73, inclusive. Compiled and published under the direc- 

 tion of M. D. Leggett, Commissioner of Patents." The first 

 volume, a royal octavo of 649 pages, was published in 1874, 

 and the remaining volumes will follow in rapid succession. 



The method adopted is strictly alphabetical, the subjects 

 being given in their alphabetical sequence, with name of in- 

 ventor, his residence, and the date and number of the patent. 

 Should full details in regard to any invention be desired, 

 they can be obtained, of course, by reference to the original 

 patent. 



DECIPHEEING CHAEEED MANUSCEIPT. 



A large number of valuable papers that had been charred, 

 apparently to a homogeneous mass, during the Communist 

 rule in Paris, have been deciphered by Rathelot. He first 

 severed the leaves by cutting the backs of the books and 

 immersing the mass in water, then subjected it to a tolera- 

 bly high temperature at a hot-air stove. The leaves, thus 

 loosened from each other by the rapid vaporization of the 

 water, were with great care separated, and were immediate- 

 ly transcribed, the writing being quite legible, as the let- 

 ters appeared dull upon the glistening black surface of the 

 paper. 8 C, Sept. 24, IS 74, 347. 



ASTRONOMY IN BEAZIL. 



The Imperial Astronomical Observatory of Brazil is a de- 

 pendence of the Central College of Rio Janeiro, and is des- 

 tined not only to teach practical astronomy to the students, 

 but to make and publish astronomical and meteorological 

 observations. The chronometers of the navy and army are 

 there regulated, and the time is given daily by signal to the 

 city. The building is situated on an eminence within the 

 city, and the government is now taking measures to improve 

 its scientific character. The director is at present in Europe, 

 with a view of procuring such instruments and apparatus as 

 may be adapted to the studies required of the institution. 



