hides with the solution of tan in close vessels, and then exhausting the
air. The consequence of this is to withdraw any air which might be
contained in the pores of the hides, and to employ the pressure of the
atmosphere to aid capillary attraction in forcing the tan into the
interior of the skins. The effect of the additional force thus brought
into action can be equal only to one atmosphere, but a further
improvement has been made: the vessel containing the hides is, after
exhaustion, filled up with a solution of tan; a small additional
quantity is then injected with a forcing-pump. By these means any degree
of pressure may be given which the containing vessel is capable of
supporting, and it has been found that, by employing such a method, the
thickest hides may be tanned in six weeks or two months.

_Printing from Wooden Blocks._--A block of box-wood is, in this
instance, the substance out of which the pattern is formed: the design
being sketched upon it, the workman cuts away with sharp tools every
part except the lines to be represented in the impression. This is
exactly the reverse of the process of engraving on copper, in which
every line to be represented is cut away. The ink, instead of filling
the cavities cut in the wood, is spread upon the surface which remains,
and is thence transferred to the paper.

_Making and Manufacturing._--There exists a considerable difference
between the terms _making_ and _manufacturing_. The former refers to the
production of _a small_, the latter to that of _a very large number of
individuals_; and the difference is well illustrated in the evidence
given before the Committee of the House of Commons on the Export of
Tools and Machinery. On that occasion Mr. Maudslay stated, that he had
been applied to by the Navy Board to make iron tanks for ships, and that
he was rather unwilling to do so, as he considered it to be out of his