First Efforts To Produce The Self-acting Engine

The Mechanical Oscillator

I conceived of an apparatus that can obtain power from the medium through the continuous cooling of atmospheric air.

It would continually transform heat into mechanical work.

It would become colder and colder, and if it only were practicable to reach a very low temperature in this manner, then a sink for the heat could be produced, and energy could be derived from the medium.

This seemed to be contrary to the statements of Carnot and Lord Kelvin before referred to, but I concluded from the theory of the process that such a result could be attained.

This conclusion I reached, I think, in the latter part of 1883, when I was in Paris. Back then, my mind was more dominated by an invention which I had evolved during the preceding year, and which has since become known under the name of the “rotating magnetic field.”

During the few years which followed I elaborated further the plan I had imagined, and studied the working conditions, but made little headway.

The commercial introduction in this country of the invention before referred to required most of my energies until 1889, when I again took up the idea of the self-acting machine.

A closer investigation of the principles involved, and calculation, now showed that the result I aimed at could not be reached in a practical manner by ordinary machinery, as I had in the beginning expected.

This led me, as a next step, to the study of a type of engine generally designated as “turbine,” which at first seemed to offer better chances for a realization of the idea. Soon I found, however, that the turbine, too, was unsuitable.

But my conclusions showed that if an engine of a peculiar kind could be brought to a high degree of perfection, the plan I had conceived was realizable, and I resolved to proceed with the development of such an engine, the primary object of which was to secure the greatest economy of transformation of heat into mechanical energy.

A characteristic feature of the engine was that the work-performing piston was not connected with anything else, but was perfectly free to vibrate at an enormous rate. The mechanical difficulties encountered in the construction of this engine were greater than I had anticipated, and I made slow progress.

The Work Of Dewar And Linde

This work was continued until early in 1892, when I went to London, where I saw Professor Dewar’s admirable experiments with liquefied gases.

Others had liquefied gases before, and notably Ozlewski and Pictet had performed creditable early experiments in this line, but there was such a vigor about the work of Dewar that even the old appeared new.

His experiments showed, though in a way different from that I had imagined, that it was possible to reach a very low temperature by transforming heat into mechanical work, and I returned, deeply impressed with what I had seen, and more than ever convinced that my plan was practicable.

The work temporarily interrupted was taken up anew, and soon I had in a fair state of perfection the engine which I have named “the mechanical oscillator.”

In this machine I succeeded in doing away with all packings, valves, and lubrication, and in producing so rapid a vibration of the piston that shafts of tough steel, fastened to the same and vibrated longitudinally, were torn asunder.

By combining this engine with a dynamo of special design I produced a highly efficient electrical generator, invaluable in measurements and determinations of physical quantities on account of the unvarying rate of oscillation obtainable by its means.

I exhibited several types of this machine, named “mechanical and electrical oscillator,” before the Electrical Congress at the World’s Fair in Chicago during the summer of 1893, in a lecture which, on account of other pressing work, I was unable to prepare for publication.

On that occasion I exposed the principles of the mechanical oscillator, but the original purpose of this machine is explained here for the first time.

In the process, as I had primarily conceived it, for the utilization of the energy of the ambient medium, there were five essential elements in combination, and each of these had to be newly designed and perfected, as no such machines existed.

The mechanical oscillator was the first element of this combination, and having perfected this, I turned to the next, which was an air-compressor of a design in certain respects resembling that of the mechanical oscillator.

Similar difficulties in the construction were again encountered, but the work was pushed vigorously, and at the close of 1894 I had completed these two elements of the combination, and thus produced an apparatus for compressing air, virtually to any desired pressure, incomparably simpler, smaller, and more efficient than the ordinary.

I was just beginning work on the third element, which together with the first two would give a refrigerating machine of exceptional efficiency and simplicity, when a misfortune befell me in the burning of my laboratory, which crippled my labors and delayed me.

Shortly afterward Dr. Carl Linde announced the liquefaction of air by a self-cooling process, demonstrating that it was practicable to proceed with the cooling until liquefaction of the air took place. This was the only experimental proof which I was still wanting that energy was obtainable from the medium in the manner contemplated by me.

Liquid Air

The liquefaction of air by a self-cooling process was not, as popularly believed, an accidental discovery. It was a scientific result which could not have escaped Dewar.

This fascinating advance is largely due to his powerful work. Nevertheless, Linde’s is an immortal achievement.

The manufacture of liquid air has been carried on for 4 years in Germany, on a scale much larger than in any other country.

Much was expected of it in the beginning, but so far it has been an industrial ignis fatuus.

By the use of such machinery as I am perfecting, its cost will probably be greatly lessened. But even then, its commercial success will be questionable.

When used as a refrigerant, it is uneconomical, as its temperature is unnecessarily low.

It is as expensive to maintain a body at a very low temperature as it is to keep it very hot. It takes coal to keep air cold. In oxygen manufacture it cannot yet compete with the electrolytic method.

For use as an explosive it is unsuitable, because its low temperature again condemns it to a small efficiency, and for motive-power purposes its cost is still by far too high.

It is of interest to note, however, that in driving an engine by liquid air a certain amount of energy may be gained from the engine, or, stated otherwise, from the ambient medium which keeps the engine warm, each 200 pounds of iron-casting of the latter contributing energy at the rate of about one effective horsepower during 1 hour.

But this gain of the consumer is offset by an equal loss of the producer.

Much of this task on which I have labored so long remains to be done.

A number of mechanical details are still to be perfected and some difficulties of a different nature to be mastered. I cannot hope to produce a self-acting machine deriving energy from the ambient medium for a long time yet, even if all my expectations should materialize.

Many circumstances have occurred which have retarded my work of late, but for several reasons the delay was beneficial.

One of these reasons was that I had ample time to consider what the ultimate possibilities of this development might be.

I worked for a long time fully convinced that the practical realization of this method of obtaining energy from the sun would be of incalculable industrial value, but the continued study of the subject revealed the fact that while it will be commercially profitable if my expectations are well founded, it will not be so to an extraordinary degree.