who shot there (and I knew many of them) that could hear well with the left ear. Even now, notwithstanding that chemical powders are almost invariably used, of six middle-aged men who are partridge-driving, if they are old hands at it, you might safely say that not one of them has good hearing with the left ear. I, for one, certainly think it is a small penalty to pay for the years of pleasure which they obtain from the sport, but in dealing with this subject plainly the fact must be mentioned.

There is another and about as stupid a way as can well be in which ears are damaged heedlessly, and it is when two men are walking close together on a return from a beat, and one of the two, regardless of the proximity of his neighbor, kills or fires at a bird or rabbit in front of them. In this case the explosion is unexpected, damaging to the ear, reprehensible, and cockneyfied.

Only once have I seen the membrane to be ruptured from this procedure, and then it healed in a few days, leaving very little deafness. It would almost seem that the force was partially expended in the very breaking of the membrane, and so in some degree diminished the shock that would otherwise have resulted. To return, howTo return, however, to the case of the big guns. When the membrane has been ruptured by the terrific force of the explosions, the damage to the hearing has not been so great as when it has remained intact, showing a similarity in this respect to the instance above quoted.

What a single explosion will on certain occasions do, oft-repeated noises will effect, as in the case of boilermakers, who notoriously become deaf. Indeed, neither in the case of big guns nor boiler-making is it to be wondered at that deafness should be produced. The structure of the ear was not originally planned with a view of its being subjected to such violent treatment, so the penalties of human progress include deafness from the causes above named. It comes to this, then-that the precise nature of the causes, no less than the precise nature of the injury, must be placed clearly before the minds. of persons in order that their ingenuity

may suggest the best methods of diminishing the risks.

In the case of naval and military officers whose duty lies close to big guns, if they take any precaution, it is usually confined to putting a little cotton in the ears. This in a very slight degree takes off some of the shockAnything which would prevent hearing the word of command would of course not be permissible. A plan which affords far more protection than cotton, and which does not interfere with hearing the orders, consists in using a species of plug which, with a little pressure, can be made to close the ears. This plug is made of the very soft clay used by artists for modelling, and is kneaded with cotton. It then forms a substance which can be moulded in a few moments by the person using it to fit any ear, while the addition of the cotton-fibre prevents the clay from sticking in the canal of the ear. I find that this is an excellent protection, and meets all requirements better than any method I have known.

It is most necessary that a few words be said to mothers, or those who have the charge of children, on the question as to what to do in case a child puts anything into its ear. It should be clearly understood, in the first place, that they cannot put anything very far into the ear; neither can what they do put in be in any way of the slightest harm so long as it is left alone. If the very simple description given of the external canal of the ear be remembered, this will be at once obvious; and it will be equally clear how serious would be the damage if any attempts were made to remove an object by unskilled hands, whose efforts would assuredly push it more deeply into the ear and injure the delicate membrane at the far end. Children will often put beads, stones, peas, or any small object into their ears for the pure fun of the thing. Provided no attempt has been made to remove the object, a surgeon accustomed to work with reflected light, which perfectly illumines the canal of the ear, can with the greatest ease remove anything which the child has placed there. But what is generally done? The mother is

will be to the advantage of such that they should in the first place apprehend the reasons why the processes of degeneration, which are natural to old age, should diminish hearing, and in the second place what mode of life tends on the one hand to delay, and on the other to hasten, those processes.

To begin with, after the age of about forty-five the elasticity of the arteries of the body becomes less; the arteries, which convey the blood from the heart to form nourishment to the tissues, become more stiff, unyielding, and brittle; so that by the time they have reached those parts which they should nourish they do not, in consequence of their thickening, supply sufficient nutriment. The nervous centres therefore suffer from malnutrition. Whatever, then, are the influences which promote degeneration will also tend to produce loss of the special senses; of these the hearing more than in the case of any other. It will be admitted generally that of all the causes which hasten degeneration, the drinking of any thing more than a very small amount of alcohol after middle life is the greatest. Next, perhaps, comes anything more than a moderate diet. Among other causes may be counted an insufficient amount of fresh air or sleep.

Now, beyond the influences above named, there is nothing perhaps which ages men so much as worry and anxiety, or women so much as strong emotion of a painful character; in other words, mental shock. From these nothing can guard humanity; but in regard to diet, air, and sleep, much can be done. I have known men who drank freely, ate freely, and were rapidly degenerating and becoming deaf, by changing their mode of life, to arrest these processes and retain fair hearing for many years, which would otherwise have been spent under far less favorable conditions as regards hearing. Similar happy results will often occur in the case of men who live at too high pressure, and undergo too much excitement, when they take a prolonged rest. With such men the term rest includes an abundance of sleep, and in all affections of a nervous nature this is absolutely essential. Mention should perhaps be made of one influence which in a measure may be modified.

It is the overstrain from prolonged and incessant nursing of a relative near and dear to them, which good women so freely bestow; for in the course of this, not only do they frequently suffer in their hearing, but, if it should be in any way affected, they strain their ears very much, being naturally anxious not to miss anything spoken by the invalid. This is very harmful to the hearing. It is not generally recognized how damaging anything like strain is to the ears, and with some persons, whose hearing is only slightly affected, the deafness is indefinitely increased by attending sermons and lectures of which they can only hear a part, and during the delivery of which the ears are kept overstrained. The exhaustion and increased deafness which follow fail to warn them how much damage they are doing to an already affected organ, although they are willing enough to recognize how damaging overstrain is to the eyes when they read small print with difficulty, or do very fine needlework by a bad light. Many persons are under the impression that the use of aids to hearing is likely to injure the ears. The facts are entirely the reverse of this, for anything which helps the hearing

avoids the strain.

From what has already been said, it would seem to be almost unnecessary to add a note of warning against the custom of pouring any fluid into the ears (which will pass on to the sensitive membrane) for the purpose of relieving pain, or against syringing the ears, unless an inspection has demonstrated the presence of anything to be removed (for a violent stream of water on to the membrane must be a shock), and yet a few drops of laudanum for the ear of a child who has earache, or a syringing for a man who becomes deaf, commonly enough form the commencement of treatment which makes the work of the surgeon more difficult than it would have been had the ears not been interfered with.

By negative management on the one hand, and by positive on the other on the lines above indicated, it will be seen that a good deal can be done toward the preservation of hearing, quite irrespective of medical or surgical aid. Longman's Magazine.

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ONE of the problems which have most engrossed the attention of mechanical engineers and students of physical science for the last thirty years has been the utilization of various sources of motive power which we find in Nature-the force of the wind, the waterfalls, solar heat, and so on-and the transport of the power which may be derived from these sources to the spots where it may be required for industrial or household purposes. The most laborious researches have been made in this direction, mechanical art going hand in hand with theoretical physics, and there being, perhaps, no other branch in which every step in advance, in either mechanical art or physical science, so much facilitated the task of the other and so much widened the conceptions of both.

How

That the productive powers of man have been increased more than tenfold since the energy stored in our coalfields has been brought into man's service by means of the steam-engine, and that the aggregate force of the steammotors which are at work in civilized communities is equal to the force of many hundred millions of men, each of which requires but a few pounds of coal for its daily maintenance, has often been said and repeated. ever, this is one aspect only of the case; the other and far more important aspect being that with the steammotor man was riveted no longer to the natural sources of energy which he found on the surface of the globe. A lump of coal became a source of motive power which could be taken to any spot of the earth-to an African desert or to an arctic wilderness, to a bare rock, to a stone quay in a harbor, to a plain, or to a marsh; it could be placed on wheels and run full speed along a line of metals, or it could be stored in a boat and used to steam that boat across the ocean. Owing to the steam-motor, energy became transportable to any amount and to any distance from its original source. It is

evident, therefore, that if any other natural source of energy be widely called into man's service, the power derived from it must be as easily transported and as easily subdivided as a cartload of coal is transported and subdivided among a number of customers.

To consider now the question of other sources of energy than coal is certainly not in the least extravagant. We have often been warned lately, from competent quarters, that if the extraction and waste of coal continue to augment as they have augmented within the last half a century, the coal-fields of the globe would be worked out within the next hundred years. Besides, owing to the very principle of the steam-engine, motive power generated by steam must remain costly, especially in the small industries where small motors only are wanted. And yet, in proportion as the needs of a civilized community grow more and more complicated, thousands of small industries develop every year by the side of the big ones. Small motors are now in demand on every farm, in thousands of small workshops, even in the bigger houses for household work, and they must be of a small size, and not be encumbered by a steam-boiler, so as to be easily placed in the corner of a room, on a small boat, on light bicycle wheels, nay, even on a flying machine. Delocalize energy, render it available at any imaginable spot, fixed or movable -this is now the order of the day

Gas and naphtha engines, in which common gas or naphtha vapors, mixed with air, are exploded under the piston of the engine, is one of the replies to this call. Steam and cumbrous steamgenerating boilers are dispensed with in these engines, which are light and handy and can be placed anywhere. Thousands and thousands of such small engines have consequently come into use with the small industries, the hothouse gardeners, the hotels, and so on, and they have already accomplished quite a revolution in the char

acters of various branches of production.* Machines working by means of compressed and liquefied gases, sold in bottles, or by means of various explosives, ought also to be mentioned under this heading; but these motors of the future are yet in their infancy.

Other sources of energy, of which Nature is so prodigal, have also been looked for. Under the scorching sun of Algeria and the Sahara, Mouchot and other Frenchmen tried to utilize solar energy, by constructing machines in which the heat of the sun was used as a fuel for a steam-engine or for other motors. The hot-water springs of Iceland and the force of the tides have also been thought of as sources of power, and the latter have been experimented upon. But the force of the wind and the energy of the rivers and waterfalls are two such great stores of motive power that they had to be utilized first, before man would go in search of energy to Iceland, or construct costly dams to utilize the tides. In fact, the old friend of man, the windmill, has lately been so much improved that in its modern garb of a self-adjustable wheel it is already a familiar feature of agricultural landscape in France and America. Suffice it to say that, according to recent statistics, more than one million of such windmills are already at work on the farms of the United States alone, pumping water, irrigating, turning churns and other dairy machinery, chopping turnips and straw, and performing all sorts of useful work.

The cheapest, as also the oldest, source of motive power is certainly running water. All great industries were born by the side of water-wheels, and our ancestors already knew the advantages of transporting the motive power of waterfalls to a certain distance, by means of aqueducts and canals used to drive water-wheels. Less costly and more efficacious systems were also thought of long ago. ready, in 1839, a French engineer, Andraud, proposed to utilize the force

Al

* More than 50,000 gas engines (350,000 horse-power), of the " Otto' type, have been sold in less than twenty years by the chief makers of this type of engines.

of the Rhône to compress air, which could afterward be sold in bottles, in retail, as stored motive power.* His idea was so correct that compressed air, transmitted along a system of pipes, really became the first means for transporting motive power to a distance. It was used with success for mining under the bed of the Loire, for building under water the pillars of the Kehl Bridge across the Rhine, and especially for piercing the Mont Cenis tunnel in the Alps. The perforating machines in this tunnel, which has a length of eight miles, were worked by motive power, borrowed from a waterfall and transmitted through strong pipes, by means of compressed air.

An important discovery, the full meaning of which is only now apparent, was made during that pioneer work. It appeared that (due precautions being taken against leakage) the loss of energy of the compressed air was diminished in proportion as the pressure under which it was transmitted was increased. A smaller volume of air under a great compression answered better than a bigger volume of less compressed air. This principle was applied later on to the transmission of natural gas from Indiana to Chicago, and, in fact, proved to be true for all modes of transmission of energy, pneumatic, hydraulic, or electrical. A whole system of transmission of motive power by means of compressed air was established later on at Paris by Popp, and it worked quite satisfactorily. True, the losses of energy under this system were very great (they were estimated at 70 per cent.), but no better means were known at that time; and when the utilization of the power of Niagara was brought under discussion in 1890, it was thought at the outset that compressed air would be, after all, the

His wording was very characteristic : "Every one must keep motive power in his storehouse, just as we now keep horses in our stables, in order to accomplish all sorts of work. Reservoirs of motive power may also be established here and there, so that one may come hither with his own vessel and buy force, just as we now take water in a public fountain. Force will then become a merchandise."