Noughts divorced, if not from beauty, from experience; not to be grasped with the brain, though the eye lends mystical help. A bit-by-bit method, dealing with moderate multiples, persuades a few. By express train the moon is only six months away; that Flying Scotsman which for eight hours bore you northwards you can perhaps, with an effort, conceive having carried you on for five hundred times as far. The sun is not four hundred times further again; you can, maybe, just visualize the journey. The old Queen was born only some three times as long ago as you and I. All previous recorded history, from Memphis or Babylon the first city, from great Cheops to great Victoria, is but fifty times longer ago than that. The post-Tertiary period is but twenty (or thirty, or forty) times longer ago than recorded history; the earlier geological periods each not more than two or three times as long as the post-Tertiary; the pre-geological period not more than half—or twice—as long ago again as all the geological eras added together. This method may help, or it may not. The persuasive “buts” and “onlys” may assist the vision of certain piecemeal and analytic minds, or may defeat their own ingenuous end, and make the years’ confusion worse confounded. The jingling millions and billions are better; the rows of huddling noughts.
With their aid, how runs the answer? How long has the world been? Ussher’s brevity is brutally avenged; the new doctors vie in prodigious estimate:
First the humble philologists, who for the evolution of human speech require a year allowance of some
80,000.
Next the anthropologists, who put man’s reign as man, since back in the early Miocene he took farewell of his anthropoid brethren, at
200,000.
Then the biologists, who for the full evolution of life, want a mere
80,000,000.
Passing from life to the lifeless earth, with the geologists we take a jump. The old man with his salt machine, turning it out like mince: how long has he been turning? All the rivers run into the sea: how many years has it taken them to bear down the sodium now found there, allowing for so much originally present, so much blown back to the shore by winds, and this correction and that?
1,600,000,000.
Sea is deep; land is deeper. How many years for the depths of the different sediments that encrust the earth to have been deposited, for the oldest Algonquins to be laid down? Maybe
1,650,000,000.
Land and sea, in even battle, have since the beginning been warring together, an age of the raising of mountains alternating with an age of the lowering of lands. There have been such and such a number of alternations. How many years have been needed to fulfil them? A rough
1,800,000,000.
Chemist joins geologist to take up the tale; together they meditate on the radioactive elements in the earth’s crust. As Paracelsus saw long ago, all stones are philosopher’s stones. Alchemy is a matter of temperature; each metal holds within itself the principle of self-transmutation. Uranium for instance, debauched uranium, goes on changing from one element into another, usually ending its fickle career as lead. The rake’s progress is long, but the spies of science have found out just how long. The rate of disintegration has been discovered, so that if there is so much uranium in a given rock, and so much lead, the age of the rock is “known.” The figure for the oldest rocks is
1,900,000,000.
Strike the balance of these four to get, as the age of the solid earth, over
1,700,000,000.
Pass from geological to astronomical mysteries. The left-hand integer rises.
The years required for the solar system to have accomplished its long journey from its nativity-place in the Milky Way—if it was born there:
3,000,000,000.
To cover the age of the moon, our child—if she was born of us:
4,000,000,000.
To account for the eccentricity in the orbit of Mercury—if one can account for it by zeros at all:
5,000,000,000.
To fit the tidal hypothesis of origin—if the true hypothesis:
5,600,000,000.
Average these four astronomicals:
4,000,000,000.
The world, then, is held to have existed as a solid globe for one thousand seven hundred million, as a separate one for four thousand million years.
As though the clues Earth affords were not obscure enough in themselves, the varying ardour of the suitors, by interpreting them most variously, has made matters worse. The physicists, half envying Genesis, have assured her she is young, always construing her shy hints as conservatively and courteously as possible. The geologists are less gallant, the chemists mere churls. From decade to decade too the estimates have varied, moving up and down in great curves, all sciences together. They were a little lower just before the last war than just after Darwin; they are higher today than at any other time. How bold was Lord Kelvin when, arguing from the laws of thermal conductivity, he demanded for the time since the crust became solid over a hundred million years; arguing from the polar flattening
