Scientific American 13, 24.11.1860
The following inventions are among the most useful improvements patented this week. For the claims to these inventions the reader is referred to the official list on another page: -
Retort for burning bone black.
The object of this invention is to obviate the difficulty hitherto attending the warping of the metal plates which retain in proper position the upper parts of the cast metal chambers or tubes in which the bone black is burned. The invention also has for its object economy in space, the parts of the retort being so arranged that the charged chambers or tubes will be exposed in the most advantageous manner to the fire, and the contents of all the chambers or tubes simultaneously burned. The invention has further for its object the perfect controlling of the fire so that the chambers or tubes may be uniformly heated, and no part of their contents injured by too intense a heat, and so forming the chambers or tubes as to resist the action of the heat, the parts most exposed being thicker than the other parts. The invention has lastly, for its object a more facile mode than usual, of connecting the coolers to the chambers or tubes so that the former may be readily attached to, and detached from the latter, and also in an improved mode of drying the bone black, after it has been used, so that the same may be deprived of the moisture it contains both by evaporation and draining, thereby greatly expediting the drying process, and rapidly preparing the bone black for the chambers or tubes. The credit of this contrivance is due to William Mitchell, of this city.