In all machinery one of the chief objects of the machinist is to reduce friction as much as possible. He makes all the joints as smooth as tools can polish, and always introduces oil or some lubricating substance into the joints. Otherwise the engine rattles with a noise proportionate to its power, and wastes its force on the friction.
In my childish days a steam-engine of any kind used to rattle so loudly that conversation was almost impossible. Now they are made with such perfection, that the vast engines in use at the pumping stations of the metropolitan drainage are almost absolutely silent.
There is the enormous hall, filled with gigantic beams and rods, and cranks, and wheels. A single man turns a little handle, and the whole machinery starts into life. Beams rock, cranks and wheels revolve, rods slide up and down, and all in a silence which is nearly appalling in its manifestation of unassuming strength. Indeed, many a hand sewing machine makes far more noise than one of those giant engines, and all because in the latter friction is avoided as far as possible, every screw is well braced up, and every joint is kept well lubricated.
Here I may observe that few sewing machines get fair play. They rattle, they squeak, they become stiffer daily, they snap the thread, and then decline work altogether. And in almost every case this is done by neglect on the part of the owner, who does not lubricate every point of the machine which works upon another.
Ladies especially are very careless in this respect, and will mostly omit three or four of the oiling points. They might just as well omit them all, as a single unoiled point will disarrange the harmonious motion of the whole machine. I have often been called in as surgeon in such cases, and have almost invariably been able to point to several spots which needed oil, and did not get it. Sometimes, out of false economy, an inferior oil is used, which speedily clogs and hardens, and stops all movement. In such a case the best remedy is to apply paraffine liberally, and use it for a quarter of an hour or so. It will soon dissolve the clogged oil, which may be worked out by turning the handle or crank of the machine.
Of course the best remedy is to take the machine to pieces, polish the joints, lubricate them, and put it together again. But this is a perilous process, and an amateur, if he tries it, will generally find himself with half-a-dozen pieces for which he can find no place. Paraffine will answer every purpose, and I have released many a stiffened machine by its use.
Then some people leave their machines untouched for days, or even weeks, and then wonder that they work stiffly. Every day the machine should he worked, if only for a few seconds, and then it will seldom stiffen. It is just the same with steamers. When they are in harbour, though the fires be out, and they are not meant to move for weeks, the engines are always turned round at least once daily.
Both these rules hold good in the animal kingdom.