The cost of manipulating the machine must be considered, that is, the required amount of power for its propulsion, and the cost of maintaining its efficient mechanical performance for a certain amount of production, or its durability, and its proneness to get out of order. Nor must one fail to take into account the required intelligence and skill to operate it.
While constantly and carefully bearing in mind the before-mentioned objective points, the prospective successful inventor in designing his machine, must carefully aim for cheapness of construction, which can only be properly accomplished by designing the various mechanical performances of the machine with the least number of parts, and of the simplest form, requiring for their proper production the least amount and cheapest kind of labor in the Pattern Shop, Foundry, and Machine Shop, and, next to the creating of efficient and durable machines, the greatest order of skill in a machine designer is required in producing simple and cheap mechanical designs.
And yet this is not all that is required from him, even in the mechanical line, but he must have such mechanical movements and parts in his machine, as will enable him to secure a good patent on it, which will insure him protection, at the same time carefully and absolutely avoiding any possible infringement on others. In a measure that can be avoided by looking up the copies of patents of similar inventions.
Another important factor in determining the general design of a machine, is the probable market for the same, as that must, in a great measure, decide the justifiable expenditure for the initial or first general cost, for bringing the successful machine into being.
INVENTORS SELDOM HAVE ANYTHING OUTSIDE OF THEIR ASPIRATIONS AND PROSPECTS.
So much for the mechanical or engineering part of the invention.