Do we at home in Scotland make too much of Scott's life and associations when we think of his poetry and his novels? Possibly few Scotsmen are impartial here. As Dr. Johnson said, they are not a fair people, and when they think of the Waverley Novels they perhaps do not always see quite clearly. Edinburgh and the Eildon Hills, Aberfoyle and Stirling, come between their minds and the printed page:

A mist of memory broods and floats
The Border waters flow,
The air is full of ballad notes

Borne out of long ago.

It might be prudent and more critical to take each book on its own merits in The Anglo-French Review

of a great writer thus discreetly. Is Balzac often judged accurately and coldly, piece by piece, here a line and there a line? Are not the best judges those who think of his whole achievement altogether — the whole amazing world of his creation - La Comédie Humaine? By the same sort of rule Scott may be judged, and the whole of his work, his vast industry, and all that made the fabric of his life, be allowed to tell on the mind of the reader. I wish this discourse had been more worthy of its theme, and of this audience, and of this year of heroic memories and lofty hopes. But if, later in the summer, I should find my way back to Ettrick and Yarrow and the Eildon Hills, it will be a pleasure to remember there the honor you have done me in allowing me to speak in Paris, however unworthily, of the greatness of Sir Walter Scott.

UTILIZING NEW SOURCES OF POWER

BY SIR OLIVER LODGE

A PINCH of coal dust, or a thimbleful of oil, represents at present the most portable form of power. If the whole of the energy resulting from these, when combining with oxygen, could be really utilized, they would yield quite a considerable store.

An ounce of oil completely burned generates, say, 1,200 British thermal units, or would heat between 6 and 7 pounds of water from freezing to boiling point; which, interpreted in mechanical power, is the equivalent of 410 foot-tons. A ton falling a height of 410 feet would generate the same amount of heat. An ounce of coal completely burned would yield slightly less energy, about four fifths of this amount. The calorific value of different hydrocarbons does not differ extensively, when reckoned by weight. But by no mechanism is it possible to utilize mechanically more than a small fraction of the heat energy generated by any form of ordinary quick combustion.

Slow combination, as in an electric battery, might be tractable throughout; but once the energy of combustion has taken the random form of heat, a great deal of it has escaped control, and only a small percentage can be directed along desired channels; that is, only a fraction is available or useful.

Still, there is a fraction which we do know how to get at and utilize; a knowledge which we owe, in any perfection and on a large scale, specially to the genius of James Watt.

A spoonful of nitroglycerin, again, represents a considerable store of energy, though of a rather violent and intractable kind. The laws regulating all this chemical or molecular sort of energy are understood.

But is there any kind of energy locked up not in the molecule nor in the interaction between molecules, but in the actual structure of each atom? Does a single atom of matter contain energy by reason of its very constitution? And if so, is there any means of getting at it?

Previous to the discovery of radium the question can hardly have been asked, or at least not asked with much hope of finding an answer. The answer is now known. In radioactive substances there certainly is a store of atomic energy, and some of the energy is liberated by the emission of flying particles which are flung off from time to time whenever the atom is degenerating or passing from a more complex to a more simple form.

And this emission of energy is very great. When it was first observed that a few grains of radium were continuously giving off a great deal of energy and yet not disappearing, some scientific men, even Lord Kelvin himself, spoke of it as a marvel or as a sort of miracle. The stuff burned, as it were, and yet was not consumed. It soon became clear, however, that there was no flaw in the law of conservation of energy. The stuff certainly possessed and certainly loses all the energy it emits, but it loses very little weight. The amount of energy it gives off per grain is so prodigious that the loss of weight is imperceptible, while the emission of energy is obvious. It is all

a question of proportion. The disappearance of a single grain of matter out of, say, a pound is only detectable by careful weighing, but the power emitted during the disappearance of a grain would be enough to raise the temperature of a ton of water from freezing to boiling point.

We must remember, however, that no such effect would be produced, even by a pound of radium, in any reasonable time; for it would take a long time effectively and fairly to lose a grain; it would take something comparable to a year. And so the power is diluted down, there is nothing violent about it, and we know no means of hastening it, nor indeed of retarding it either. It is a remarkable fact that whether the bit of radium be made red-hot in a furnace, or cooled hundreds of degrees below zero by liquid air, its rate of disintegration remains practically constant; it steadily gives off its intrinsic energy unaffected by the molecular commotion or stagnation which we call heat or cold.

The energy emitted by a radioactive substance is atomic and intrinsic, not molecular and incidental. Heat energy depends on the motion of molecules. Chemical energy is concerned with the rearrangement of atoms in the molecule. The energy we are speaking of is involved in the constitution of atoms themselves.

About this last kind of energy we should have known nothing had it not been for the discovery of spontaneous radio-activity; in other words, had it not been a property of large and heavy atoms to throw away small portions of themselves and become lighter atoms of a slightly less complex character.

People sometimes speak of radium as if it were unique. Not so; it is a striking member of a class, and it serves well to illustrate the properties of that class. Every now and then an

Only now and then does a radium atom get to this explosive stage. For every one that thus exerts itself, in the course of a year, there are about 3,000 which remain quiescent for that period. But directly one shot has been fired, the rest of that particular atom is remarkably unstable and does not settle down into quiescence again till it has fired off four more, converting itself each time into a different element. Some of these shots follow each other quite quickly, barely giving time to the experimenter to examine the properties of the intervening substances. Yet these substances are real elements with chemical reactions of their own, and with a characteristic spectrum; their peculiarity is that they are shortlived. Each transitory element differs in atomic weight from the one above it by the same approximate amount 4 (hydrogen being 1); so, when the whole five particles have been flung away, the atomic weight of the result is no longer 225, but more like 205 or 207, the atomic weight of lead. And there are many reasons for thinking that the common inert element 'lead' is what it has become, when its epoch of activity and instability has come to an end. On that view the plentifulness of lead would be due to its stability; it would be like a population with a very low death rate.

Thus the residue is still heavy, not much has been lost, and even the projectiles might be retained by a simple enclosure holding the original radium and its products, so that in that case no loss of weight would be readily

perceived. Yet loss of weight does accompany the evolution of energy, though it is incomparably smaller than any loss of substance entailed in the process of combustion.

The most active chemical combination the greatest energy per unit weight of combustible material is

the burning of hydrogen in oxygen. This emits heat to the value of 4,000 units of heat for every gramme of water formed by the combination. But by the time that a gramme of radium has gone through its changes, a million times this quantity of energy would have been emitted.

But then, as we know it is not emitted quickly, the process takes a long time, and at present we know no means of either hastening or controlling it. It is in that respect like volcanic energy or the energy of lightning; it occurs at its own time, not at ours; the reaction is violent enough, but is beyond the directing power of life and intelligence; until some further discovery is made.

Let it not be supposed, however, that only the atoms of radio-active substances possess this atomic energy. It is pretty certain that every kind of material atom must possess it; some more, some less; but for the most atoms the energy is all locked up in their intimate structure, and is quite inaccessible. The radio-active elements are those which do not keep the energy completely locked up. Once an hour one out of thirty million atoms goes off with violence, and continues. to fire at known though not quite regular intervals five times, till it becomes quiescent again. It thus gives away the secret of a vast store of energy. Had there been no spontaneous radioactivity we should not have known that atoms were anything but sedate particles; moving about rapidly, it is true, but retaining their own identity

and absolutely permanent in composition, if, indeed, they had any composition and were not mere points.

Far otherwise is the truth. Every atom is a complicated structure, a region of law and order, and in all probability no element is permanent. Disintegration is probably only a question of degree. The unstable ones attract attention and enable measurements to be made. Some even of these are fairly sedate, and, like uranium, last millions of years. Radium lasts at most a few thousand years; but other elements there are which are so prodigiously violent that they last only a few minutes. These, therefore, make themselves conspicuous even in small quantities, but naturally are extremely

scarce.

The point for present consideration, however, is not the rate at which different elements choose to give out their store of energy, but the existence of this store and its marvelous abundance. The particles that are shot off from radium are shot with a speed quite amazing-about one fifteenth that of light. To get some notion of this speed we may compare it with the highest speed of a bullet. During the time taken by a rifle bullet to fly without resistance from the muzzle of a rifle to a target 300 yards away, the a particle simultaneously shot off from radium, if it met with no obstruction, would have traveled the 3,000 miles from London to New York. The time needed is only a quarter of a second.

is so; but think how many atoms there are in any visible speck of substance. Take a milligramme of radium - that is, take one seventieth of a grainand ask how many projectiles such as we have been describing are fired off by it each second. The number is surprising; it is no less than thirty million, even from radium itself; and the number of projectiles is really five times as great as this, if the products of disintegration are not allowed to escape. Thirty million projectiles a second, each with a fifteenth of the speed of light, come away from a milligramme of radium every second, yet the speck will last a thousand years before it is half exhausted.

Chemical combination is 'not in it' with energies such as this. And this is the kind of energy which is locked up, and at present inaccessible, in every atom of matter. A little arithmetic would enable us to paraphrase the late Sir William Crookes and say that if all the energy in an ounce of matter could be extracted and fully utilized it would be enough to lift the German Navy and pile it on the top of Ben Nevis.

Sir Ernest Rutherford reckons that the gaseous emanation primarily given off from radium after firing its first shot this emanation being itself a chemical element which is sometimes called Niton is so spontaneously active that it actually does radiate energy at the rate of ten thousand horse power per pound, and that the total emission during its short life is equivalent to continuing this rate of emission for six days. And even then only a fraction of its energy would have been got rid of, for it has only changed to another substance which still has plenty more.

Undoubtedly if the progress of discovery enables us to get at and utilize the energy locked up in a ton of ordinary matter per diem no further mo

tive power would be needed. And if further we found ourselves able to liberate any considerable portion of such energy in a short period of time, the explosive violence would be such that the very planet would be unsafe.

It is to be hoped that no such facilities will fall to the lot of an enterprising scientific nation until it is really and humanely civilized, and is both willing and able to keep its destructive power in check. Humanity is not ripe for any and every discovery; but in due time, and when it can be applied to useful and beneficent ends, I doubt not some such power as that here foreshadowed will be attained.

The Observer

RUIN OR RETRENCHMENT, THE CHOICE BEFORE GREAT BRITAIN

THE debate on the Consolidated Fund Bill has caused something like consternation in the country. The chancellor of the exchequer told the House of Commons that the nation is on the way to bankruptcy. Mr. Chamberlain said that—and yet remains chancellor of the exchequer. He had no remedy to offer, and no plans for retrenchment, and seemed to think he had done his part when he had mentioned that we are drifting to ruin. He had no difficulty, indeed, in showing that the prodigalities of the government had been connived at and encouraged by the House of Commons. Facing his critics, who were now talking economy, he stated that only the previous day a member had come to him with a memorial to the prime minister, which more than half the members of the House of Commons had signed, calling upon the government to increase the pensions of civil servants who had retired and whose bargain with the state was completed.'