never understood very well what that could be, and I understood it no better when it was called Potential Energy. I understood that such a stone had weight; but that was mere Force, or Pulling strength. What was this Latin Energy; and how did the stone get it; and how was a stone lying on the roof of a house, or on a mountain, different from any other stone?

The answer seemed to be that the stone could fall, when its Latin Energy would become Greek. In other words, if you took away the house, or the mountain, the stone would fall, not by its own weight, but because it was being pushed downwards, just as if I should pick up a stone and throw it down. But if that were so, how was I to tell the difference between this Energy that made stones fall from the roofs of houses, and the Force that made you and me fall, and everything fall? Newton would have been surprised, 1 fancy, to learn that his famous apple fell because of its Energy. But perhaps apples on trees have not got Energy of Position; only apples on the roof of a house.

I should have liked to ask these learned and distinguished writers whether a stone lying, not on a roof, but on the ground, had any of this enchanted Energy; or a stone lying, not on a mountain, but on a plain. And if not, how high must the stone be to get it. I wanted to know where Energy of Position left off, and Force began. If you should put a stone in a basket, and lower it halfway down a well, would that stone have Energy of Position? It seemed to me that you might go right down to the middle of the earth, finding nothing but Energy of

Position all the way.

I was tempted to fear that there must be a mistake in the Story of Creation; and that it was really this Energy that inhered in, and could never be taken from, ponderable Matter. Thus the rigid and definite meaning of Force had turned out to be-Potential Energy. Perhaps the author has written here more truly than he knew. Yet I think it evident that to the trained mind there is something peculiar and fascinating about stones lying on the roof of a house; they have a charm that other stones have not. The magic attribute is called by one of my authorities "advantage over a Force," namely the Force of Gravity. But then it seems to the untrained mind that all the tiles of the roof, and the house itself for that matter, have the same advantage. The real advantage which the stone lying on the roof of a house has over a stone lying on the ground is your advantage, because it is easier for you to throw a stone downwards than upwards. But in both of those cases it is your energy that moves the stone, with its own weight added in one case, and subtracted in the other.

However that is just what science, speaking through the mouth of its priests, will not allow. According to them, when you throw the stone down there is some other power at work beside your push and the earth's pull; there is this mysterious Potential Energy which has been inside the stone all the time. It therefore seems to be a scientific case of demonpossession. The demon of Latin Energy enters into some stones but not others. It prefers stones on the roof of a house if it can get them, but if not, it will take stones on mountains, just as the demons in the gospel,

when they were cast out of the man, entered into the swine. It is remarkable that those demons behaved very much like Energetic ones, for they drove the swine violently down a steep place into the sea.

I hope it is not irreverent to say that I do not believe in this Gadarene Energy. I do not see why it should be called in to do the work that Force is already doing. It would be just as easy to discover a kind of Force that would do what Energythe Greek Energy that is energetic-does. Force is pulling things towards the middle of the earth. But everything does not get there. Some bits of Matter get in front and hold the others back. And the power by which they do so is not Energy, it is Force of Position.

I can even find another magic stone, as an example, a stone falling into a glass of water. As the stone falls down it will push the water up. Here is a plain case of Latin Force, the Force that does what you would expect Energy to do.

IV

The Story of Creation does not end here, unhappily. For its author, not content with his Potential Energy, which does what Force was doing, has gone

on to invent yet another kind of Energy, which does the whole work over again.

He does this very easily. For just as he first divided Power into Force and Energy, and next divided Energy into going and stopping Energy, so now he goes on to divide the going, or, as one might say, the Energetic Energy, again into three kinds, one of which does what Force and Unenergetic Energy both do.

'Each kind of kinetic Energy has separating, combining and neutral motion. Example of Separative -a stone thrown upwards; example of Combining— a stone falling; example of Neutral-a top spinning in the same place."

So therefore, what really makes the stone fall is neither Force nor Latin Energy, but Greek Energy which is going the wrong way;-shall I call it Antienergetic Energy?

And I see no reason why the learned writer should not have carried his scientific terms, with their rigid and definite meanings, a good deal farther. For after the stone has fallen it is likely to bound up again, and that will clearly be an example of Redistributive, or Ultra-Energetic, Energy. And then it will be almost sure to fall again under the stress of Katasynthetic Energy; unless it should happen to lodge on the roof of a house, and thereby offer a rare example of Extrapotential, not to say Extravagant, Energy.

V

The whole of this laboured nonsense flows from a mistake at starting, the mistake of trying to think of strength as two rigid and definite and indestructible strengths; whereas strength is like a wave with two faces which are neither rigid nor definite nor indestructible, but are forever changing into one another, as the wave's crest becomes the trough, and the trough, the crest; and Force and Energy are not two Powers, but two names for one Power, working To and Fro.

The author of the Story of Creation has let his mind be tripped up by bad language. It is not worse language that that of other text-books; I chose his book because it claimed to be better written than other books, to be indeed a school-book; and language that would be bad in any book is damnable in a schoolbook. If the teacher's words trip up his own mind, what must they do to the child's mind? Has not Topelius given us a glimpse in his delightful story of the little boy fresh from his first geography lesson, trying to talk to the maidservant in words like oblate spheroid and equator?

As soon as men, however learned and distinguished, put their minds to sleep with Mediterranean words, they begin to gabble like little Walter. While they are talking in Babu, they are thinking like Andró