It is a patchwork, only, that is obtained by one common method used to obtain a newly designed machine. Namely, the manufacturer purchases every type of machine, already marketed to perform a given work, and adapts one part from one machine, another part from a second machine and perhaps still another part from a third machine. Such a design must always be a compromise, and it is seldom possible to obtain the original working efficiency of the several parts in the new machine because of the necessary compromises.
A second point that the manufacturer is apt to overlook is the importance of including the most minute of details in his general high standard of manufacture. For instance, he elects to use copper for a water container, but he forgets to provide that every bolt and rivet and screw, no matter how small, shall be of a rust-resisting metal. The small part capable of rusting is as much an eyesore to the purchaser and in certain conditions can do as great damage as though the manufacturer had not spent the major sum to insure his rust-resisting container.
And a third point: sometimes a manufacturer neglects to make certain of a perfection of detail in the factory that will produce one hundred per cent uniformity in his product. Thus vacuum cleaner manufacturers, merely by installing an equipment that would measure for them, under actual conditions of service, the correct air displacement of the particular machine tested, could eliminate any possibility of lack of uniformity in their product. Further, it would take no more time for the inspection than is at present accorded to the routine reading of current consumption. Yet up to this time we know of no vacuum cleaner factory that has installed this comparatively simple and inexpensive equipment.
