Max Nitsche-Niesky recommends the following in _Neueste Erfindung_.:
Good coke is ground and mixed with coal-tar to a stiff dough and pressed
into moulds made of iron and brass. After drying for a few days in a
closed place, it is heated in a furnace where it is protected from the
direct flames and burned, feebly at first, then strongly, the fire being
gradually raised to white heat which is maintained for 6 or 8 hours. The
fire is then permitted to slowly go down, and when perfectly cold the
carbon is taken out of the furnace.
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