The scrub head nodded.  ‘Oh! go on.  Go on.’

’It would mean a change in human conditions that I can only compare to the discovery of fire, that first discovery that lifted man above the brute.  We stand to-day towards radio-activity as our ancestor stood towards fire before he had learnt to make it.  He knew it then only as a strange thing utterly beyond his control, a flare on the crest of the volcano, a red destruction that poured through the forest.  So it is that we know radio-activity to-day.  This—­this is the dawn of a new day in human living.  At the climax of that civilisation which had its beginning in the hammered flint and the fire-stick of the savage, just when it is becoming apparent that our ever-increasing needs cannot be borne indefinitely by our present sources of energy, we discover suddenly the possibility of an entirely new civilisation.  The energy we need for our very existence, and with which Nature supplies us still so grudgingly, is in reality locked up in inconceivable quantities all about us.  We cannot pick that lock at present, but——­’

He paused.  His voice sank so that everybody strained a little to hear him.

‘——­we will.’

He put up that lean finger again, his solitary gesture.

‘And then,’ he said. . . .

’Then that perpetual struggle for existence, that perpetual struggle to live on the bare surplus of Nature’s energies will cease to be the lot of Man.  Man will step from the pinnacle of this civilisation to the beginning of the next.  I have no eloquence, ladies and gentlemen, to express the vision of man’s material destiny that opens out before me.  I see the desert continents transformed, the poles no longer wildernesses of ice, the whole world once more Eden.  I see the power of man reach out among the stars....’

He stopped abruptly with a catching of the breath that many an actor or orator might have envied.

The lecture was over, the audience hung silent for a few seconds, sighed, became audible, stirred, fluttered, prepared for dispersal.  More light was turned on and what had been a dim mass of figures became a bright confusion of movement.  Some of the people signalled to friends, some crowded down towards the platform to examine the lecturer’s apparatus and make notes of his diagrams.  But the chuckle-headed lad with the scrub hair wanted no such detailed frittering away of the thoughts that had inspired him.  He wanted to be alone with them; he elbowed his way out almost fiercely, he made himself as angular and bony as a cow, fearing lest some one should speak to him, lest some one should invade his glowing sphere of enthusiasm.

He went through the streets with a rapt face, like a saint who sees visions.  He had arms disproportionately long, and ridiculous big feet.

He must get alone, get somewhere high out of all this crowding of commonness, of everyday life.

He made his way to the top of Arthur’s Seat, and there he sat for a long time in the golden evening sunshine, still, except that ever and again he whispered to himself some precious phrase that had stuck in his mind.