character and influence which constituted their chief attraction, and imparted to them their extraordinary value. As a bachelor of arts living chiefly among those of my own standing, or with the very oldest of the undergraduates, I had no opportunity of forming any judgment of the moral and religious state of Christ Church during the period at which I have arrived; but I have every reason to believe that it was in a state of progressive improvement. Some young men of what was called the Evangelical party had now come into residence there; and as they were amiable as well as religious, and as there was sufficient good-feeling among their contemporaries to secure them against molestation, even if not to obtain for them a certain respect, they had an influence for good beyond the sphere of the small circle in which they lived. With this exception I do not remember that the idea of religion as a practical rule of life was ever suggested to me while I was at Christ Church, although dissuasions from immorality in one shape or another were occasionally put before me by those who had authority over me. More than this was certainly done at other colleges; for I remember that a friend of mine who was at Oriel used to tell me how great an impression had been made upon him by his excellent tutor Hawkins, the present Provost, in the course of walks which he had been asked to take with him. At Christ Church the only way in which religion, as such, was put before us was in the public prayers of the college, than which nothing could well have been more adverse to its proper influence. The services were so managed that it would have been hardly possible for any one to make a good use of them even had he wished it; and I do not think that such a wish was largely shared. Little or no care was taken to secure even the decent behaviour of those who attended chapel as a general rule; and it was only when that behaviour broke out, as was sometimes the case in the evening, into the most disgraceful irreverence, that authorities interposed to control it. The names of those present used, when I was at Christ Church, to be noted by the registering student during the time of the service itself; and the period chosen was especially during the Creed, when every one turned round towards the Communion-table. During the greater part of my undergraduate time the most irregular and unpunctual attendant at the chapel was the Dean himself. But an improvement in these respects was set on foot before I left Christ Church, and has, I believe, continued to proceed. One practice which existed in other colleges was unknown at Christ Church-I mean that of forcing the men to go to Communion once a term. This, as far as it went, was an advantage; though the alternative was, after all, one between profaneness and irreligion. VOL. III. SS About this time the Union Debating Society, which was first established somewhere about the year 1823, had begun to assume much of the importance which afterwards belonged to it. I have no doubt that it has been in two ways of great use to Oxford; as a means of moral improvement, to say nothing of its advantages as a school of oratory and parliamentary practice to those of whom so many are likely to be called into positions where such a preparation must prove of signal use to them. The Union Society, by placing men of all the various colleges upon a footing of perfect equality, has operated more than any other single agency towards the removal of those invidious distinctions and college rivalries to which I adverted in my last paper. There can be no doubt also that it has been of great service in furnishing useful and innocent subjects of conversation and pursuit to many, who before it existed were led to seek pleasure in topics and interests of a less praiseworthy character. For a long time the authorities of the University discouraged the Union, and even after they ceased to discourage it, were unwilling to give it any thing like an avowed protection; but I believe they have learned by experience that its tendency to draw undergraduates from the characteristic studies of the University is far more than counterbalanced by its advantage in another direction; and that, even in the light of an academical institution, its benefit has been far from inconsiderable in widening the range of useful knowledge, and bringing the light of modern political experience to bear upon the history of ancient times. Need I add, that the great living representative of the benefits-both intellectual and moral-of the Oxford Union Society is to be seen in the person of Mr. Gladstone, who, as an undergraduate of Christ Church, was alike the foremost orator of the Union and an example to his companions of the possibility of combining youthful virtue with that deportment of humility and social kindliness which is best calculated to win others to the imitation of it. I now bid adieu to Christ Church, not without regret; and must reappear, if at all, in another neighbourhood. Proposed Substitutes for the Steam-Engine. THE present year has been remarkable for the large number of machines invented for the purpose of superseding steam, in at least some of its lighter tasks. Many of these are due to French engineers; being further proofs, if any were required, of the great activity now displayed in France in all matters of mechanical invention. Two of these new engines are especially interesting, as illustrating that all-important law in modern physics, the correlation or convertibility of forces. By this is meant that the forces of inanimate nature, such as light, heat, electricity-nay, even the muscular and nerve forces of living beings-have such a mutual dependence and connection, that each one is only produced or called into action by another, and only ceases to be manifest when it has given birth to a fresh force in its turn. Thus motion (in the shape of friction) produces heat, electricity, or light; heat produces light, or electricity; electricity, magnetism; and so on in an endless chain, which links together all the phenomena of this visible universe. As a metaphysical principle, this is as old as Aristotle, and may be found dimly foreshadowed in the forcible lines of Lucretius: Haud igitur penitus pereunt quæcumque videntur, Rem gigni patitur, nisi morte adjuta aliena.”* But the rediscovery of this law, as a result of experiment, is due to English physicists of our own day; and it is so invariably true, and the produced force is always so perfectly proportioned to the force producing it, that some† have gone so far as to revive a very old hypothesis in philosophy, supposing that all the forces of nature are but differently expressed forms of the Divine Will. As a corollary to this law, it follows that many a force of nature, *Lucret. lib. i. 250-65. † Dr. Carpenter, Philos. Trans. 1850, vol. ii. hitherto neglected because of its position or intractability, may be turned to practical account by using it to produce some new power, which may be either stored up or transmitted to a distance, and so can be employed wherever and whenever it is required. Thus, in the first machine we propose to notice, a M. Cazal has just hit upon a plan by which to use the power of falling water at a considerable distance. He employs a water-wheel to turn a magneto-electric machine (of the kind used for medical purposes, on a very large scale), and the electric force so obtained may be conveyed to any distance, and employed there as a motive power. In this way a mountain-stream in the Alps or Pyrenees may turn a lathe, or set a loom in motion, in a workshop in Paris or Lyons; or even (as has been remarked), if a wire were laid across the Atlantic, the whole force of Niagara would be at our disposal. The idea is at present quite in its infancy; but we are told that the few experiments hitherto made show that such an engine is not only very ingenious but perfectly feasible, and (most important of all) economical. The second engine gave promise of considerable success when first brought out in Paris about eight months ago. It was invented by a M. Tellier, and proceeds on the principle of storing up force, to be used when wanted. It has long been well known to chemists that a certain number of gases (as chlorine, carbonic acid, ammonia, and sulphuretted hydrogen) can be condensed into liquids by cold or pressure, or both combined. Of all these gases, ammonia is the most easily liquefied, requiring for this purpose, at ordinary temperatures, a pressure only six and a half times greater than that of the atmosphere. A supply of liquid ammonia obtained in this manner is kept by M. Tellier in a closed vessel, and surrounded with a freezing mixture, so that it has but little tendency to return to the gaseous state. A small quantity is allowed to escape from this reservoir under the piston of the engine; and the temperature there being higher than in the reservoir, the ammonia becomes at once converted into gas, increasing thereby to more than twelve hundred times its previous bulk, and so driving the piston with great force to the top of the cylinder. A little water is now admitted, which entirely dissolves the ammonia; a vacuum being thus created, and the piston driven down again by the pressure of the air without. M. Tellier employs three such cylinders, which work in succession; and the only apparent limit to the power to be obtained from this machine is the amount of liquid ammonia which would have to be used, about three gallons (or twenty-two pounds) being required for each horse-power per hour. There is no waste of material; for the water which has dissolved the gas is saved, and the ammonia recovered from it by evaporation, and afterwards recondensed into a liquid. M. Tellier proposed to use his engine for propelling omnibuses and other vehicles; but it would appear that it is too expensive and too cumbrous to be practically useful: there can, however, be very little doubt that the principle will be used with success in some new form. A patent has quite recently been taken out for such an engine in England. It will be perceived at once how the ammonia-engine illustrates the law of storing up force. It originates no power of its own, but simply gives out by degrees the mechanical force which had been previously employed to change the ammonia from a gas to a liquid. Lenoir's "gas-engine" has been more successful; for, although but a few months old, it has been already largely adopted in Parisian hotels, schools, and other large establishments, for raising lifts, making ices, and even-for what is not done nowadays by machinery? -cleaning boots. In London, it was lately exhibited in Cranbourne Street, and is now used for turning lathes and for other light work. This engine, like the ammonia-engine, is provided with an ordinary cylinder, into which coal-gas and air are admitted, under the piston, in the proportions of eleven parts of the latter to one of the former. The mixture is then exploded by the electric spark; and the remaining air, being greatly expanded, drives up the piston. When the top is reached, the gas and air are again admitted, but this time above the piston, and the explosion is repeated, so that the piston is driven down again. The most ingenious part of the whole thing is the mechanism by which the electric spark is directed alternately to the upper and lower ends of the cylinder. This cannot be satisfactorily explained without a diagram, but is brought about (roughly speaking) by connecting either end of the cylinder with a semicircle of brass, which is touched by the "rotary crank" in the course of its revolution. The crank is already charged with electricity, and so communicates the electric spark to each of the semicircles in turn. The cylinder is kept plunged in water, so that there is no fear of its overheating by the constant explosions. This engine has cheapness for its main recommendation. A half-horse-power gas-engine (the commonest power made) costs, when complete, 657., and consumes two pennyworth of gas per hour; while the cost of keeping the battery active is about fourpence per week. An engineer of Lyons, M. Millon, has since proposed to use, instead of coal-gas, the gases produced by passing steam over red |