This is a simple mechanical arrangement, but
one which is found to be of immense benefit, and which, in the writer's
opinion, is far superior to the usual practice of marking off the sheet
with a chalk line, and then dressing off with hand knives. The last
length of the mill table forms a weighbridge, and a hydraulic crane
lifts the sheet from it either on to the warehouse floor or the tramway
communicating with the shipping quay.
* * * * *
APPARATUS USED IN BERLIN FOR THE PREPARATION OF GELATINE PLATES.
I.--MIXING APPARATUS FOR GELATINE EMULSION.
The mixing vessel--a porcelain kettle capable of containing twenty
liters, made at the Royal Porcelain Factory at Berlin, whose products
are unequaled for chemical purposes--is also the boiling vessel, and,
therefore, fits tightly, by means of the tin ring with the wooden
handles, on to a large water bath. The light-tight metal lid, which
can be permanently affixed to the kettle, then supports a stirring
arrangement of fine silver, which dips into the emulsion and has blades
formed like a ship's screw.
The arrangements for injecting the silver vary. The simplest consists of
a large glass vessel containing the silver solution, which is closed
by a glass stopper, and terminates below in a funnel running to a fine
point.
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