for the combined working of many tools, which formerly
received their direction from man. In using a tool man is the direct
agent, in using a working machine the transmitting mechanism is the
direct agent, so far as the character of the several acts of
production is not stamped upon the form of the working machine itself.
The man placed in charge of a machine determines whether it shall act,
but only within very narrow limits how it shall act. The two
characteristics here brought out in the machine, complexity of action
and self-direction or automatic character, are in reality the
objective and subjective expression of the same factor--namely, the
changed relation of man towards the work in which he co-operates.

Some of the directing or mental effort, skill, art, thought, must be
taken over, that is to say, some of the processes must be guided not
directly by man but by other processes, in order to constitute a
machine. A machine thus becomes a complex tool in which some of the
processes are relatively fixed, and are not the direct expression of
human activity. A machinist who feeds a machine with material may be
considered to have some control over the pace and character of the
first process, but only indirectly over the later processes, which are
regulated by fixed laws of their construction which make them
absolutely dependent on the earlier processes. A machine is in the
nature of its work largely independent of the individual control of
the "tender," because it is in its construction the expression of the
individual control and skill of the inventor. A machine, then, may be
described as a complex tool with a fixed relation of processes
performed by its parts. Even here we cannot profess to have reached a
definition which enables us in all cases to nicely discriminate
machine from tool. It is easy to admit that a spade is a tool and not
a machine, but if a pair of scissors, a lever, or a crane are tools,
and are considered as performing single simple processes, and not a
number of organically relative processes, we may by a skilfully
arranged gradation be led on to include the whole of machinery under
tools. This difficulty is of course one which besets all work of
definition.

But while it is not easy by attention to complexity of structure
always to distinguish a tool from a machine, nothing is gained by
making the differentia of a machine to consist in the use of a steam
or other non-human motor.

A vast amo