ollow it wherever it is used. By
patience and industry he may instruct some one in the use of it,
but in these days there is no chance for a great economic success
in making just one machine, or in fact any machine for which there
is not a large market. Hence, we will confine our attention to
machines made in such large quantities that the complete
supervision of manufacture, sale, and use is beyond the capacity
of one person.

For all such machinery the design must more or less conform to the
thought and habits of work of all concerned. Some of the most
direct designs have failed to meet with success just because the
inventor did things in an unusual way. The unusual way is a blind
way, and is difficult to find. In some instances it amounts to no
way at all, for it is never used.

If a radical change in design is to be made, the new machine
should be one that will be the most readily understood. Obscure
parts or unusual means should be avoided.

If moving parts must be covered, some way should be provided for
convenient observation. It is the obscure departure that is the
most troublesome, and it is the obvious thing that offers the
least resistance to progress.

There is a chance to progress by obvious devices, and such
progress is enjoyed by all, from the makers to the users. It
stimulates their weak but wholesome appetite for progress.

Technical View Insufficient.

But whether the clear view of the designer is due to peculiar
fitness for seeing such things, or to proper application, the fact
remains that this clear view of the technical side is insufficient
in itself. The man with the clear view must also realize that
others do not get the same view. He must know that the mind
automatically takes in things of interest to it and wards off
others. Even when the individual apparently tries to comprehend
something in which he has no special interest, it only results in
a superficial mental impression, one that has no appreciable
effect on the actions.

This failure of mankind in general to grasp the advantages of a
new mechanism as it appears on paper is only a slight part of the
troubles to be encountered by a progressive designer.

He has to contend with habits of thought and action of all the
human beings affected by the new machine. This includes the entire
group of men in the manufacturing plant in which the machine must
be made, the business organization both in this plant and the one
in which it