It is ofttimes a complex subject. The different systems. Steam is at the head. Electricity. Compressed air. Transmission of power. Various systems. Belts. Ropes. Chains. All systems are merely that of transmitting power. Water and steam are our original sources of power. The systems of transmission, or distribution of power. The boiler room. Types of boilers. The best type. Mechanical stoking. Boiler settings. Longitudinal section. Cross-section. Horizontal section. Smoke connections. Steam connections. Foundations for boiler settings. Gas engines. Steam engines. Transmission by belts and shafts, or by electric motors. Compressed air for foundry and forge shop. Compressed air in the machine shop. Motors for individual machines. The system adopted. Lighting dynamos. Driving the steam hammer in the forge shop. Boiler and pipe coverings.

In considering the question of power and its transmission to the different points in the plant where it will be required, we are confronted by a rather complex subject, and one which has been much discussed by many competent engineers in nearly all the mechanical journals during the past few years. Steam is now, and for probably an indefinite time will be, the favorite and controlling power generator, since to it we owe all other forms, not of power, but of the transmission of power. The various methods and theories have had able champions in the special line in which they have been interested, and rival claims have been ingeniously advocated to prove that they were the best methods to be adopted for nearly all conditions.

One class have proven, to their own satisfaction at least, that while electricity is still in a very imperfect state of development and generally very imperfectly understood by a large majority of mechanics, it is to be the coming power for all purposes and may be used under nearly all conditions. Many of these claims have been well substantiated and the fact is that to-day there is a far greater and more general use of electricity in transmitting power than was thought possible even ten years ago. The ultimate limit to its usefulness no one can foresee.

Again, the advocates of compressed air have shown that this has many advantages as an easily transmitted and very useful power, and in its special sphere is doing very efficient and admirable work. New applications are constantly being found for it, and many operations formerly performed by hand are very much quicker, cheaper, and better accomplished by its use. The sphere of its usefulness has broadened very much in the last few years and now we find it in nearly all up-to-date shops, for a large variety of purposes. In this it does not take the place of electricity, but rather is used in conjunction with it, or with steam power for the purpose of providing the compressed air, as may be most convenient.

The old-time mechanic is, however, apt to "pin his faith" to shafting and belts as the most reliable method of transmitting power, perhaps because he is better acquainted with this method; while the younger men are prone to argue the efficiency of rope transmission as the proper method. Many examples of efficient service by rope transmission might be cited, yet for the general purposes of a machine shop it is doubtful if it will ever replace leather belting altogether.

Recently the utility of transmission by chain has been revived and the interest in the subject very much increased by the improved forms adopted by later inventors. It is often exceedingly useful for the transmission of power within the limits of a single machine, formerly for operating feeds, and later for transmitting the principal power of the machine. Properly constructed, this system would seem to have a broad and practical field of usefulness in the future.

But all of these methods and systems, when reduced to the plane of practice in providing for the power plant of manufacturing concerns, are simply so many different methods of transmitting and distributing power, since it is to water or steam that we must look for our original power. We are confined, then, to these two sources of power - water and steam - and where the location does not provide us water power we must accept steam. Assuming the latter conditions in our manufacturing plant we must provide for steam as our source of power.

This having been settled, the best means of transmitting the power to the machines on the ground floor of the machine shop, to those on the gallery floors, to those in the tool room and pattern shop, and to the forge shop, foundry, and carpenter shop, must also be considered.

The question of boilers will naturally come first, and, in this connection, the type best adapted to the work; also the best method of setting them to produce the most efficient results. Next, the type and the dimensions of the engine, and the manner of its connections. And lastly, the method of transmitting the power to the machines to be driven.

In arranging our power plant we begin with the boiler room. We shall need a working capacity of at least 500 horse-power. This may be distributed in a battery of boilers of 100 horse-power each. One extra boiler is added so that in case of an accident to one of them, necessitating repairs, five of them may still be in proper working condition. Four of these boilers will be needed to run the engine, which leaves a margin of 100 horse-power with which to supply the necessary steam for other purposes about the plant.

Under ordinary conditions a sixth boiler may be added, giving 200 horsepower for these purposes. By this arrangement there is the additional advantage that the boilers may be cleaned one at a time without shutting down the power.