follow in the agricultural produce of the world, would more than supply the place of all the power we derive from coal and other sources at the present time.

Now, corn at present can only be made to render energy artificially by burning. It may be that this is the only possible means that we shall ever have; but physiologists have not as yet told us the exact manner in which the energy of the union of the constituents of corn with oxygen is converted or directed to power in the animal, but from the amount of power yielded by the animal, compared with the food consumed, it seems probable that somehow or other the union of corn with oxygen in the animal yields directed energy and not energy in the mob form, such as we have in the steam engine. Should there be an artificial means of directing power, corn would supply eight or nine times the amount of energy which it does as at the present time used, and hence would do away with the necessity of coal at all. Now, I do not mention this as a prophecy in the least. The steps to be taken are enormous before it can be realized. I believe that very few attempts have been made and very few efforts have been directed to its realization. I only mention it as shewing that there are instances which give us a glimpse of the fact that there are numberless possibilities for wind and waterfalls in the future.

Now, the mechanics of the universe, no less than those of art, depend on the transmission of energy. We may consider the methods of transmission are three. Our artificial methods, those of nature, existing on the surface of the earth, and those outside the earth. Referring for a moment to our artificial means, we have the methods existing on the earth and those existing outside the earth. Now, the most important consideration with regard to the transmission of energy or power, is the question, what proportion of the power transmitted must be spent in transmitting it, or what amount of power must be spent in the transmission of energy, and on what circumstances does this proportion of power depend? Is it universal? As far as we can tell it is. In all artificial means the transmission of energy requires the expenditure of a certain amount of directed energy. With all transmissions on the earth we find the same. I shall not now stop to consider these, but will mention them. We have currents of wind and water. If power was not spent in the motion of these, the earth would be no place to live upon. We have sound, and although the distances to which sounds may be heard are not exactly limited by the actual loss of energy in their transmission, still, from our knowledge of the properties of air, we may say definitely that the power has to be spent in transmitting sound. Lastly, we come to the waves of the sea, a source of power which, it always has seemed to me, has been singularly neglected. It is one of the very largest natural sources of power upon the earth, and, although it is not very difficult to make waves of the sea propel a boat, as has been instanced in this room-to make the boat propel herself, as it were, by her own rocking-still it is a matter to which has seldom, until, perhaps, quite recently, been paid proper attention. I believe Mr. Power brought forward, in this room, a method by which he made a ship, merely by her own rocking, work herself along by the waves. But, besides that, the obvious power of the waves of the sea, as they destroy our coasts, is such that it is rather extraordinary to me that this

source of power has not only been neglected in actual practice, but has been neglected by those who have sought for a means of replacing our coal. I do not for a moment say that the waves provide such means, but I say that if we could utilize the waves as a source of power, it would be the greatest saving of all, for we should not only save our coal, but we should save our country which is inevitably going underneath the waves as time goes on.

These are the principal means of transmitting power on the surface of the earth-there are others, such as earthquakes, but, however we look into them, they are all attended with a loss of power in the transmission of energy. If we look outside the earth, into inter-stellar space, we see the case is very much changed. Here we have two means of transmitting energy, and only two heat or life, and the motion of the heavenly bodies. With neither of these, so to speak, can we perceive that there is any sensible resistance, or power required in the transmission. The distance at which we can see the stars is a sufficient evidence of the case with which the heat waves and the light waves move through space, and the regularity in the motion of the heavenly bodies is a sufficient evidence, so to speak, of the freedom from resistance which they experience. Nevertheless, arguments are not wanting to shew that even here there is probable resistance, although it is so small that we cannot measure it by any terrestrial measure. There is one problem in astronomy which philosophers are entirely undecided upon; that is, why the whole of the heavens is not a blazing light like the sun. If space is infinite, and the stars are distributed through space as far as they are, as we see them, there can be no spot in the heavens in which, if we went far enough, we should not see a star; and, under those circumstances, it would be one blaze. The way out of this is to assume that, although very slight, there is a resistance, or what we may term a loss, of power in the transmission of the heat which limits the distance to which it may be transmitted. If we turn to the passage of our heavenly bodies, the argument is somewhat similar. A few domesticated comets form the main evidence which we have of any resistance in the planetary system. These come earlier and earlier, and it is not so long since we were all on the qui vive expecting to see, or promised that we should see, an old friend returning earlier than usual, and plunge into the sun. However he passed away much, I should say, to the relief of the nervous, and somewhat, I fear, to the discomfiture of astronomers. Unfortunately, this is not the only discomfort which astronomers are experiencing at the present moment. When I first went over in my mind what I should say this evening, I formed the conclusion, that I should be able to set before you a very definite ground for or against the resistance of bodies moving through the air, such as the planets, but something has happened in the meantime. The Radcliff astronomer of Oxford has announced a discovery. Until a fortnight ago such was the confidence in the science of astronomy that it was thought that the past and future of all astronomical phenomena could be so told and predicted that a second of time difference between any observed and calculated phenomena was a sufficient ground on which to base a confident prediction that the length of the day was increasing; the earth was stopping in her rotation and the moon was going slower, or

as it was supposed leaving the earth. Now the discovery of Mr. Stone, the Radcliffe Astronomer, is of altogether another kind, but not less important and appears to cut away the very foundation of all this laboriously built edifice. He has discovered a mistake which appears to have occurred from an endeavour to bring about what is called a forced agreement. With the very best intentiou, no doubt, certain numbers have been altered to a very small extent a process which is not altogether unknown in book-keeping, though sometimes called under another name--and the result, as it is very often in other cases, was not confined to the immediate idea of those who made the alteration; the unit of time with which all these things were measured was actually altered, and the result is that Astronomers have been measuring the heavens with a variable unit of time, and before they can see where they are at all, all the calculations, at any rate, those which have been made during the last sixteen or seventeen years must be gone through over again. You cannot say really whether the earth is going slower, whether the days are increasing, whether the moon is leaving, or anything with certainty about those matters, until these higher calculations have been corrected. This discovery was announced, as I daresay you are all aware, in a paper read at our Society only a fortnight ago. Whatever the result may be, I give it to you on the authority, of probably one of the highest authorities, of this day; if it had come from anyone else, no one would, of course, have taken any notice of it, but it comes from the Radcliff Astronomer, at Oxford, Mr. Stone, and as there were a number of observers with him at the time, I feel it impossible to say what I was going to say before, viz.: whether the bodies were resisted or not resisted in inter-stellar space. Of one thing we may be perfectly certain, that whatever the result of the new calculations may be, this discovery of Mr. Stone's will mark an epoch in the history of astronomy.

But I must come back to my subject. The energy we derive from the sun comes to us in the form of sunshine in a somewhat singular manner. It comes to us in not exactly mob form, but in a very highly directed and disciplined form, but so scattered that one might almost liken it to an army of highly trained skirmishers. Before we can actually use the power so given in the form of energy, it must be collected. Now there are two methods of collecting the energy of sunshine. I may say as regards art, any action that is undertaken in the conversion of sunshine into power by man is subject to very great difficulties indeed, owing to its scattered form. But nature has her own means, as of course you will know, and the two methods are:-(1). To collect the energy at the spot where it falls for a long time. (2) To collect so as to aggregate the rays of the sun, and collect the energy over space. Nature collects it over time in the growth of vegetables, and art has no means whatever of performing this operation. On the other hand nature apparently has no means whatever of aggregating the sun's rays, and that we may really do in art. The lens of a reflector will clear the rays which fall on a large space and put them on to a smaller space, and, as is well known, with the burning glass we may produce effects in that way. There of course the glass does not represent the powers, but the system has not been without its advocates, and we have all heard of the rays of the sun collected in a reflector having been concentrated on a small

boiler and driving a small steam engine. However, any such methods of working by art so obviously undertaken at such a disadvantage, that the cost is altogether out of proportion to the result, nor is there any hope of ever altering this since the apparatus for collecting them must be distributed over the whole area from which it is collected. Besides that, even if we could collect it, the value of the sun's rays, at all events to this country, in promoting vegetable growth, is too great to permit of their diversion to any other purpose.

That

Now the question as to whether nature performs her work efficiently or not in collecting the sun's rays in the growth of plants, is one which has never been attempted to be solved by anybody, I believe. But nature's method here is probably wasteful, as are indeed all nature's methods-we will say apparently wasteful, but, however, they are very effective, and the energy collected over a long time, whether it be in the grass, or in the corn, or in timber, or in coal, may be further aggregated by the expenditure of power, and nature herself has provided the means, first of all, in the teeth of animals, and secondly, in their moving about to collect the force. Part of the directed energy of the sun which is in the vegetable is spent by the animal in moving himself about, but there is a residue. If now we take the case of a horse, and the vegetable food is collected for it, we find that the Horse will, as it were, live on something under two acres of highly cultivated ground. Take the ordinary power of a horse as a horse power, which is rather under the mark, this gives 300 foot pounds of work of course the number seems big, but that is only because we take a million as our unit-as the power to be required from the acre in a year of good agricultural ground. represents the directed energy which is really acquired from the sun's rays through corn and through horses. Now this energy is only available on the spot where the sun falls. If we want it at another spot part of it must be spent in causing the motion. If we take things as they are, a very large portion of this energy is spent in agriculture, but there is a residue, and it has been man's object ever since, I believe, the beginning of the world to make this residue as large as possible. The steps by which he has done this has been by devoting the residue to the amelioration of the conditions of agriculture. He first of all improves his land, drains it, and so on, and then finally, not until practically quite recently in this country at all events, he makes roads. Now the effect of making roads is perhaps shown better by comparing the distances over which a horse or a man will carry their own food. Without roads it is very difficult to put a limit because it is dependant on the underground; but something which we may average at about 300 miles would be the limit. With a good road I have put the distance to which a man or a horse could carry their food at 1,000 miles, but it would really comparatively be greater than that.

Now, here comes a most remarkable thing when we come to canals. On a canal a horse will draw a load of 100 or 120 tons 2 miles an hour. On a railway a horse or locomotive will only draw its corn about one-eighth as far as it would on a canal; that is, moving at slow speeds, it would carry it about half round the earth, or about 12,000 miles. These distances are, in a certain sense, theoretical: they are obtained by comparing the work of the horse by the day with its gross work. But they are not far short of the actual results shown

in carrying corn from the middle or West of America to this country. As a matter of fact, we are, and have been for years, receiving corn carried more than 1,000 miles over land, and three or four thousand miles over sea to this country, with an increase of price of something like 25 per cent. in the corn, which represents a possible expenditure of energy of 25 per cent. in the corn. It may be more than that in the case of coal. Working it out theoretically, this transmission of corn from America would really involve an expenditure of energy of some 25 per cent. Add to that the other accessory cost, and we get 25 per cent. in cost and corn. This is no ideal case it is an actual result; and if we look at it in another way we see the result still more clearly. Coal is in England, horses are in England, steam engines are in England. We can plough either by coal through the steam engine or by horses. It is found, not on a small scale, but on the largest possible scale, to pay better to spend our coal in bringing corn from America to feed our horses upon in England to plough with, than it is to spend the coal in England to apply on the ground in England. That points to two results. It points to the extreme cheapness-the extreme smallness, as I pointed out-of the cost of transmitting energy in the form of corn and coal, and also to the very great expense which at present there is in distributing actual work -in distributing and adapting the works of the steam engine to the particular operations which are better performed by And this is no small case. In England there is at the present time more work performed by horses than by the whole of steam power put together, and, at the same time, a very large proportion of the food of these horses-it is impossible to say exactly what-is brought from America.

man.

Now, the conclusion to which I would call attention is this -that what is true at the present time of corn may, if the scientific predictions are realized, be true in a very few years of coal. And if this result is accomplished it will make an entire change in the circumstances which determine the favourite spots for living on this earth. If by the salubrity of our climate, by the freedom of our politics, or by the facilities, natural or mechanical, which we here have for life, this country is a favourite spot to live upon, we need no more fear the inability of our coal fields to supply coal for mechanical power; we need fear no more disastrous consequences to our prosperity from that cause than we at present perceive from the inability of our soil, owing to its limited extent to supply corn for the animal power which we at present use.

The Pulpit Record.

SATURDAY, MAY 19, 1883.

transitoriness of life, describes it movingly as a pilgrimage, and proves how little it signifies how we may be entertained by the way; but if he is of a brisk, stirring temperament, we shall find him planning a thousand things for daily comfort and convenience which his hearers who are behind him in the theory of the pilgrim life do not think worth while. Perhaps, though occupying themselves but little with the shortness of life as a whole, their turn of mind is that very uncomfortable one which regards the particular stage through which they are now passing as too short, incomplete, and therefore unimportant, to bestow pains and interest upon. The waiter upon change will put off action till the change comes. Where is the good of reforms, renovations, and freshners, when the time may be so short? We prefer, as a rule, the energetic preacher of this world's vanity, who, though life is short, or because it is short, gives its minutes their due, and encumbers his heirs with no dilapidations. Not but what this may be overdone: for, of course, there is a strong disposition in busy minds to think things worth while that are not.

There are undoubtedly seasons and spaces when it is wise to wait-when it is not worth while to commence any undertaking, great or small. There are studies which it is not worth a man's while to take up, pursuits which it is not worth his while to follow, minutes and half-hours which it is not worth while to fill with an occupation. No doubt we have all our peculiar notions on this head. It does not seem to us worth while to read at dinner-time, or out of doors, or to set oneself to learn a language in recurring spare moments; these acts come under the same category of virtues with the old housewife's economy of time which makes her sit up in bed to knit stockings in the dark, or re-thread her needle, at infinite expense of time and eyesight, to save an inch of cotton.

There are a vast number of small industries that are not worth the while of a man with one settled occupation which engages a fair portion of his time. We have not much faith in the achievements done in odd minutes. We believe there is usually more loss than gain by them, and that manners and conversation both suffer where there is this trick of thinking it worth while to pull out some implement of labour-pen, pencil, or needle, at times when other people are content to seem unemployed, and are only busy in being agreeable and placing themselves at the service of their company.

We have all our opinions, but in truth no one can judge for another what is worth while. Ifa man has any one commanding talent, nothing is worth his while that distracts him from it, though it may carry the air of a respectable occupation. Wordsworth did not think it worth his while to read any authors but those who have clothed in words the grand catholic feelings that belong to the grand catholic situations of life, and clothed them in such words that human wit must despair of bettering them; yet it is well worth other people's while to read books of a lower range and of quite another order. People of genius constantly misjudge in this way. They are right in the abstract-right as far as they themselves are concerned, but not right for those they would legislate for. Thus it is very true that the passion for grottos a hundred years ago was absurd.