The favorable features in machine designs are:  directness of mechanism for the purpose; its simplicity and its efficiency; its adaptability to the habit of thought and action of makers and users.

The obstacles to its success are any of the features it may have that cannot be readily comprehended by those who are to build, sell, buy, and use these devices.  It is of little value for real success for a machine to be one that is readily understood by a draftsman or manager, or that it is one that may be made to perform wonders in the hands of a skilled expert.

The real economic success depends on the number of machines that will be used.  The number of machines that will be used depends on the readiness with which the real workers take hold and manipulate the machine.

To get a true conception of the value of a machine, it is necessary to look at the showing of a business engaged in its manufacture.  In estimating the value of a machine-building business for this purpose it is customary to speak of its “good will.”

Easiest Way to Improve.

Inventions of complete novelty and of great economic value have attained success going in opposition to this principle of conformity to the habit of the world.  But the easiest way is to direct improvements and inventions along lines that are the most readily assimilated by the minds of the beings to be considered, and this may be said to be one of the master-keys to economic success.

The work of building the first model of a new machine may be under the direct supervision of the inventor, and if only one machine is to be made, the inventor can follow 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.