'You've made it wonderfully clear so far Sir,' said the McKay, 'but what I don't understand is how we got here.'
'That I think I can explain,' Menes answered. 'From the earliest times it was necessary to bring air into the mines and my forefathers devised a very efficient system. You will be aware that water has, mainly, the same constituents as air and that the gills of a fish are only a cleverly constructed piece of mechanism which enables it to extract what you call oxygen from this medium. A gigantic shaft was made down which, when it was opened, many thousand tons of water would descend from the sea—distant only sixty miles from the Atlantean capital. This water was filtered through many layers of rock and mineral deposits then evaporated by currents of the earthshine until the oxygen was extracted and renewed the air even in the deepest workings of our mines.'
'But wasn't the whole plant smashed up in the earthquake? asked Nicky.
'A truly wonderful arrangement,' Axel commented; 'but the essential part of this great filter—forty miles in extent— was ten thousand feet, below the surface of the earth and so remained unimpaired. It works to this day, just as a mighty dam would still check the course of a river although the nation which had made it were long since dead. Your sphere was swept from the ocean bed and carried to these subterranean regions by the inrush of the waters.'
'But they can't keep rushing in,' objected the McKay; 'once this deep shaft was filled with water there would only be gentle percolation at the bottom and therefore very little downward current from the top.'
Menes shook his head. 'I fear you underestimate the wonderful scientific achievements of my ancestors. The shaft is comparatively narrow at the sea bed and when it is filled the pressure of the water, striking its bottom with tremendous force, sets a series of immense lever stones in motion which close its top. They are released in turn, every twelve hours, when the tunnel has emptied, by the action of the tide. The whole process is automatic therefore and operates without the aid of man.'
'A truly wonderful arrangement,' Axel commented, 'but surely, without attention or replacement any such mechanism would have worn out by now?'
Menes smiled again and the slightly superior note in his voice was softened by its gentleness. 'My son, you are but as little children striving in the dark compared with that great people who were swept away. The Pyramids of Egypt, which far surpass any monuments you have yet erected, are small by comparison with the great works which my nation undertook. They only represent a feeble effort made by a few survivors from the cataclysm to copy a state which it is not possible for your minds, as yet, to conceive. Those little pyramids have lasted for five thousand years, virtually unimpaired, and you still have no true knowledge of the reason for their building. In another ten thousand years they will still be there, neither man nor nature—short of another vast upheaval—has power to destroy them. How then can you even suggest that similar works upon a far greater scale, operated by natural causes, the turning of the tides and the bi-diurnal releasing of cataracts greater than any waterfalls you know, should become worn out in the time which has elapsed since their installation.'
For a moment they were silent all striving to adjust their 292
minds to such a gigantic undertaking accomplished by the puny hands of man. Then the McKay said slowly:
'You'll forgive me, Sir, but I'm still in the dark about how we arrived in the middle of a great haul of fish.'
'That too I can explain,' Menes turned towards him. 'When the brute creatures had been created in large numbers it became something of a problem to feed them, for all supplies had to be transported to such a great depth in the mines. In order to save themselves this labour our ancestors conceived the idea of utilising the tunnel by which the water is conveyed to the filter beds giving us air, to trap large quantities of fish.
'You doubtless know that oil means death to all sea creatures, so gushers were conducted to points which formed a circle half a mile in diameter round the opening of the tunnel in the ocean bed. When the work was completed tlie inrush of the first waters at each tide forced up the oil from the lower earth, forming a circular wall of polluted water. The fish could not pass through it and so fled to the centre of the circle and, except for those who escaped by swimming upwards were caught in the current and drawn down through the narrow opening into harbours especially constructed to take the catch. It was your good fortune to be engulfed in such a haul when the main tunnel was nearly full and thus conveyed safely through the automatic locks, instead of being swept below in the first great spate of waters. If that had happened you would have been carried past the harbour entrance and dashed to pieces, or left submerged in the miles of underground cisterns which feed the filters. Have I now made the reason for your miraculous escape quite clear?'
The McKay smiled a little wryly. Man-planned construction on such a tremendous scale was at first a little difficult to grasp, but he recalled Doctor Tisch's statement that the artificial irrigation works of Moeris, in Egypt, were four hundred and fifty miles in circumference and three hundred and fifty feet deep. Yet the Egyptians were considered by these people as only decadent imitators of their race. He thought too of the underground railway systems which serve the teeming millions of the great modern capitals and had to confess to himself that there was nothing at all impossible in a civilisation which had lasted eighteen thousand years before the Flood engineering this wonderful network of subterranean canals.
'Yes, I understand that Sir,' he said at last, 'and obviously it must be so. We couldn't have got here in any other manner but there's one point I'm not quite clear on yet. Granting the big air-filtering reservoirs and harbour, and the locks, were all safe thousands of feet under the ground, and that your ancestors had harnessed natural forces like the tides and oil-gushers to work the system so that it is still working—surely the earthquake jammed the whole caboodle at the upper end when Atlantis met its Waterloo'?'
'You speak in riddles my son, but my mind, now attuned to yours, picks up your meaning. You are right of course. Over fifty miles of the tunnel leading to the original sea bed was shorn away, the oil-gushers—no longer checked— leaked into the ocean, polluting the water for a hundred miles around instead of spurting only for a few moments each half-day so that the currents could cleanse the area for fresh shoals of fish between catches. But Zakar saved us. Zakar took command and fought death in the darkness for the salvation of his people through forty days and forty nights of terror and confusion.
'By far the greater portion of our mines were flooded and destroyed. Only this comparatively small area was saved through the accidental blockage of shafts and channels. Whole legions of .the brute creatures with their Atlantean overseers died almost immediately, others must have been imprisoned in galleries and chambers by falls of rock and compelled to surrender to death a few days later. Yet in the section which remained there were forty thousand of the beast slaves and Zakar had the power to direct their energies through his will.
'The earthshine had burst into a roaring volcano two miles from here, thus plunging this area into total darkness. Ten thousand slaves were burnt to death in the endeavour to restore it to its proper channels, but at last Zakar got it under control again. Then he drove his brute battalions to the task of capping the oil-gushers so that they would throw up their fountains only under pressure. Lastly he cleared the locks of fallen debris, blocked the new tunnel entrance on the ocean floor, drained out the water into now useless chambers, and reconstructed its opening on the original lines. When all was done no more than a few hundred slaves remained alive but their twice-daily supply of fish was assured to them and the twelve Atlanteans settled down to live on this site in Petru's house.'