...photographIng the spectra of stars, except for its grained texture, meets the need of the astronomer ut all points. This plate possesses extreme sensitiveness...make up by successive installments, as the weather ru;iy permit, the total long exposure which may be needful. The power of the eye falls off as the spectrum...

...the aid of the new dry plates, with gelatin films, Introduced by Mr. Kennett, I was able to take np again, and this time with success, the photography...for this reason, as I soon found to be necessary in tils climate, it can be exposed again to the same object on succeeding nights; and so make up by successive...

...gelatine plate, except for its grained texture, meets theueeds of the astronomer at all points. It possesses extreme sensitiveness; it is always ready...any position; it can be exposed for hours ; lastly, it does not need immediate development, and for this reason can be exposed again to the same object...

...observatory, over the process of Daguerre, and even over that of wet collodion. The silver-bromide gelatine plate, which I was the first, I believe, to use for...on succeeding nights ; and so make up by successive instalments, as the weather may permit, the total long exposure which may be needful. The power of...

...observatory, over the process of Daguerre, and even over that of wet collodion. The silver-bromide gelatine plate, which I was the first, I believe, to use for...on succeeding nights ; and so make up by successive instalments, as the weather may permit, the total long exposure which may be needful. The power of...