“Simplicity does not mean fewness of parts. Reuleaux showed long ago that with machines there was in every case a practical minimum number of parts, any reduction below which was accompanied by serious practical drawbacks. Nor is real simplicity incompatible with considerable apparent complexity. The purposes of machines being continually more complex, simplicity must not be looked upon as absolute, but only in its relation to a particular purpose. There are many very complex-looking pieces of apparatus which work so directly along each of their main branch lines that they are in reality simple. It is usual that the first attempt to carry out a new purpose results in a very complicated machine. It is only by the closest examination of the problem, the getting at its very essence, that the machine can be simplified. If a problem is only soluble by extremely complicated apparatus, it becomes a question whether it is worth having. Closely allied to simplicity is Directness. Certain transformations are unavoidable, but the fewer the better. In some cases they may be as indispensable as the abused middleman in matters economic. In the first machine to do something mechanically hitherto done by hand, the error is often made of trying to imitate hand-work rigorously. The first sewing-machine was, I believe, made to stitch in the same way as a seamstress. It was not until a form of stitch suitable for a machine, although unsuitable for the hand, was devised, that the sewing-machine was successful. The first railroad carriages were practically stage-coaches put on trucks, from which the present carriages have only very slowly been evolved.” Directness. A few years ago it was usual to attach pumps, dynamos, and other machinery to their actuating engines by pulleys and belts. To-day in most cases the connection is direct; all the energy which would be absorbed by intervening wheels and leather is saved. In steam-turbines one and the same shaft carries the steam-vanes and the armature of an electrical generator. In saw-mills of modern design a very long steam cylinder is provided with a piston directly attached to the saw carriage. The same principle gives high economy to the steam hammer and pile-driver of Nasmyth. Hammers, drills, cutters and other tools driven by compressed air are directly attached to the rod which holds the piston. In like manner Saunders’ channeling machine, actuated by steam, has its cutters attached to its piston, so that a blow is dealt with no intervening crank-shaft, lever or spring.