CHAPTER II

THE MUMMY AT THE FEAST

ONE OF THE MOST CURIOUS effects of what we may call the new cosmic outlook, the attitude engendered by the study of astronomy, is that we can regard our globe with a spirit of cold detachment. The man of science seems to transfer himself a quarter of a million miles away—say, to the moon—and describe the earth as if it were the possession of an alien race. Essentially, he says, a large metal globe, measuring about 7,900 miles in diameter, and weighing about (here one likes the “about”) 6,000,000,000,000,000,000,000 tons. Being surrounded by a shell of gases, some of which have formed great oceans of water, the metal has rusted and disintegrated at the surface; and the rubbish, and the molten matter squeezed from below, have, under pressure, formed a tough skin of rock between forty and fifty miles in thickness which binds the globe.

This would give us a very solid and durable structure but for two circumstances. The metal interior must have a very high temperature and be subject to an enormous pressure. The temperature rises one degree (Fahrenheit) with every fifty feet of descent into the crust, and the boiling point of water must be reached about two miles from the surface. At fifty miles the metal should have a temperature of about 5,000° F. The terrific pressure no doubt prevents the metal from taking a fluid or molten form, but when we reflect that the belt of rock is, in comparison with the fierce interior, hardly thicker than the shell of an egg, we are not surprised that molten matter bursts or oozes from below through every pore and fissure. If the Earth is still contracting, as is generally believed, the pressure must increase and the strain on the rocky shell become more severe.

The second great condition of instability is that the globe whizzes—it is almost absurd to say “turns”—on its axis once in twenty-four hours. At the Equator, in other words, the surface of the ball gyrates at a thousand miles an hour. It is a great “fly-wheel,” and a hundred things indicate its sensitiveness under the strain. Only a short time ago a very wet week-end poured 6,000,000,000 tons of water upon the district of London, and it can be proved that such a sudden load actually depresses the solid crust. It is believed that the shifting of the North Pole means that the earth wobbles under the shock of heavy local falls of snow and rain. That it shudders and trembles habitually is registered infallibly by our sensitive modern instruments, and to lie awake on the fifth floor of an hotel during even a moderate earth-quake, as I have done in New Zealand, is a peculiar experience. Sometimes a great fault or dislocation in the seams of rock discovers itself, and the masses of rock snap together with a jolt that shakes large cities into bloody ruins.

It is intimated that 13,000,000 people have met their deaths by earthquake and volcano during the last three thousand years. This is, however, a small toll of the thousands of millions of human beings who have trodden the Earth during that period, and it merely indicates, for the present, a condition of what we should call “comparative stability.” The question of interest is whether there is any danger of the malady increasing as the Earth contracts.

When we study the face of our Moon we get the impression that the danger is worth considering. It is related that the ancient Egyptians had an unpleasant habit of checking the flow of mirth at a banquet by introducing a mummy and sending the thoughts of the guests forward to an unattractive future. The Moon is the mummy at the feast of humanity. “Such you will one day become,” its livid face seems to call to the astronomer. It will be realised in the course of this work that the period of cosmic life depends on size or mass. Heat is life in the case of these globes, and smaller bodies lose their heat sooner than large bodies. Hence, though the Moon is not older than the Earth, and is indeed generally believed to be a daughter of the Earth, it has—with certain reserves which I will discuss presently—reached the state of cosmic death long before us. The Sun, a globe of 2,000 trillion tons, is in, or not long past, the prime of life. The Earth, 332,000 times less in volume, has almost lost internal life, but may maintain a surface-life for millions of years. The Moon, with less than 1∕80th the volume of the Earth, is a dead and rigid world.

So one asks with interest how the Moon died, and at first sight, as I said, the inquirer may be alarmed. The face which the Moon presents to us is almost entirely blotched with what seem to be the craters of extinct volcanoes. It looks as if at some date the heated metal interior had revolted at length against the pressure of the shell, and had oozed out, by 200,000 pores, some of gigantic dimensions, upon the surface of the globe.

In the days of feeble telescopes the volcanic nature of these dark rings was undoubted, but with the enlargement of the power of the instruments many astronomers began to interpret the features differently. The telescope consists essentially of two parts; a great lens or mirror for gathering as much light as possible from the distant object and a magnifying glass, or small microscope, for enlarging the image of the object at the intensified focus of the lens or mirror. The more light you get—the larger the diameter of the lens or mirror—the greater the power of magnification you can apply, and, virtually, the nearer you bring the object. With the Lick telescope, which has a 36 inch lens, or the Yerkes telescope, which has a 40-inch lens, or the Mt. Wilson reflecting telescope, which has a 60-inch mirror, a magnifying power of 1,000 can profitably be applied. Larger powers may of course be used, but photographs taken with these larger powers will show that you lose in detail what you gain in size. We, are, however, not so near the end of telescopic development as men thought ten years ago. The Canadian Government has now, in its Astrophysical Observatory, a reflecting telescope with a 72-inch mirror, and the Mt. Wilson Observatory has erected one with a mirror 100 inches in diameter. New principles of construction also are being tried, and we may before many years see the Moon as one sees landscapes in a mountainous region.

As it is, a powerful telescope has, in a sense, the effect of bringing the moon so close to us that we can detect single objects 440 feet long. With the larger and dimmer power, indeed, an object only 295 feet long could be individualised. The range of our eye on Earth must not mislead us. Here we gaze horizontally through the thick strata of the atmosphere, but in examining the Moon we gaze through the shortest depth of the dense layers, and there is no air (or a negligible quantity of air) on the Moon to dim its features. We have therefore a remarkable knowledge of the surface of the Moon, and the excellent photographs that have been published, especially by the Lick Observatory, make it familiar far beyond the range of amateur astronomy.

And the first impression one has is, as a vivid astronomical writer has said, that one is gazing upon a “volcanic charnelhouse.” The sharp line between light and darkness, as the Sun rises, and the unfading brilliance of the stars when they pass behind the disk, show that the Moon has no appreciable atmosphere. Whether it may have an inappreciable atmosphere, or wisps and pools of thick gases lying in the hollows, it is not worth our while to seek. Gases surrounding a globe tend to drift away into space, unless the mass of the globe is sufficient to hold them by its gravitational power. It is doubted by many if the mass of the Moon is great enough to exert that control, and they therefore doubt if it ever had an atmosphere. However that may be, a number of delicate tests convince us that the Moon is to-day practically airless and waterless, and its aspect encourages the belief that this has been its condition for ages.

Its isolated hills and its ranges of mountains rise, steeply, to a height which, relatively to the size of the moon, makes them More majestic than our Andes and Himalaya. Gravitation is, on the Moon, one sixth feebler than it is on the Earth, and the masses of molted rock which have boiled through the crust have risen like stupendous fountains turned into ice. There has, moreover, been no “weathering”—no corrosive action of gas and water—and the frozen masses of metal rise into innumerable cones and peaks, and fling sharp and weird shadows over the levels. The lunar Apennines, 450 miles long, soar into some three thousand steep and rugged peaks, touching a height of 18,000 feet. The Alps have 700 peaks, rising to 10,760 feet. The peaks of the Doerfel Mountains reach 26,000 feet; of the Leibnitz Mountains 27,000 feet.

In addition to these colossal outbursts of igneous matter, which have congealed into lofty mountain ranges, there are other features which are generally interpreted as volcanic. The dark large areas which were once thought to be the bottoms of evaporated seas and oceans are now generally regarded as lava-plains. Possibly the thin crust succumbed, in an early stage of development, and the molten lava flowed evenly over the vast areas. There are also bright rays or streaks, radiating far over the disk from some of the craters, and, since they are brightest at full moon, it is thought that they are ancient lava-streams, on the surface of which a fine ash or crystalline layer has gathered. In fine, there are the craters, but the nature of...