1080 Traxsactions of the American Institute. 



grapliy, for publication in the journals devoted to this branch of the 

 arts. 



Mr. Bierstadt exhibited a very large and beautiful collection of 

 positive collodion, or collodio-ehloride prints, transferred to colored and 

 bronzed paper by William P. Dewey, of Paris. 



The impressions of bronze work and coins were particularly 

 remarkable for their fidelity to the originals. 



Mr. Boyle suggested the use of mounts of graded tints for land- 

 scape work, which would admit of representing a blue or clouded 

 sky, with a foliage green or earth tint in the foreground, thus giving 

 a more truthful representation than can be obtained by the use of one 

 uniform tint throughout the dark or shaded i;)arts of the entire 

 picture. 



Mr. Bierstadt presented several of the collection to the Section. 



Mr. Mason presented four sterographs showing variations in crys- 

 tillization of bromide of ammonium. 



The Section then adjourned to the first Tuesday in March. 



March 1, 1870. 



Vice-President Bogardus in tlie chair ; Mr. O. G. ^Mason, Secretary. 



Professor Tillman called attention to the nomination of otficers for 

 the ensuing year, and offered the following ticket : 



For President, Charles A. Joy ; Vice-Presidents, Abraham 

 Bogardus, Chas. W. Hull, Henry J. Xewton ; Secretary, Oscar G-. 

 Mason. 



"Which was unanimously recommended for appointment by the 

 organizing committee. 



Mr. J. F. Adams exhibited and explained his magnetic stereoscope, 

 in which the pictures for exhibition w'ere placed in a receptacle above 

 an octagonal frame or cylinder containing a series of small magnets, 

 so arranged as to retain the picture in position for examination by 

 the magnetic attraction exerted upon strips of lined iron, with which 

 the ends of the slides were bound. The ingenious device attracted 

 marked attention, and its merits were discussed by several members. 



Mr. Robert Price exhibited an improved letter and picture envelop, 

 80 constructed as to be used for mailing, like the ordinary envelop, and 

 ■when opened for removal of manuscript matter, the picture envelop 

 yet remained uninjured. 



