The Home of Mankind Read online

  But it is extremely doubtful whether we could exist if it were not for this vast reservoir of heat, which we call the sea. The geological remnants of prehistoric times show us conclusively that there have been times when there was more land and less water than to-day, but invariably these were periods of intense cold. The present balance of 1:3 between land and water is an ideal one if our present climate is to continue indefinitely, and we shall all of Us he much better off if it does not get disturbed.

  This vast ocean which encircles the entire globe (in this respect the ancients had guessed right) is, like the solid crust of the earth, in constant motion. The moon and the sun, through their power of gravity, attract it and cause it to rise to a considerable height. Then there is the heat of the day which takes part of it away in the form of vapour. The cold of the polar regions covers it with ice. But from a practical point of view as something directly affecting our own well-being, the air-currents or winds must be accorded first rank for their influence upon the surface of the ocean.

  When you blow long enough on your plate of soup, you will notice that the soup begins to move in the direction away from your mouth. When certain air-currents hit the surface of the ocean for years and years in succession, they will cause ‘drifts’ which will move in a direction away from that particular current. Whenever there are a number of air-currents blowing from different directions, these different ‘drifts’ will neutralize each other. But when the winds are steady, as they are for example on both sides of the equator, the drifts become veritable currents, and these currents have played a very important part in the history of the human race and in making certain areas of the world inhabitable which otherwise would be as cold as Greenland’s icy shores.

  HUNDREDS OF MILLIONS OF YEARS AGO THE CONTINENTS SEEM TO HAVE BEEN VERY DIFFERENT FROM TO-DAY

  A map of these ocean rivers (for that is what many of those currents really are) will show you where they are situated. The Pacific Ocean has a number of such currents. The most important of these, as important in its way as the Gulf Stream of the Atlantic, is the Japan current, or Kuro Siwo (which means the Blue Salt Current), which is caused by the north-east trade-winds. After having done its duty by Japan, it crosses the northern Pacific and bestows its blessings upon Alaska, which it keeps from being too cold for human habitation, and then, turning sharply towards the south, gives California its agreeable climate.

  But when we speak of ocean currents we think first of the Gulf Stream, that mysterious river, some fifty miles wide and 1500 feet deep, which for untold centuries has kept the northern part of Europe well supplied with the tropical heat of the Gulf of Mexico and which accounts for the fertility of England, Ireland, and all the North Sea countries.

  The Gulf Stream has an interesting career of its own. It begins with the famous North Atlantic Eddy, a drift rather than a current, which like a gigantic maelstrom turns round and round in the central part of the Atlantic and enfolds within itself that pool of semi-stagnant water which has become the home of billions of little fishes and floating plants and which, as the Sargasso or ‘Seaweed Sea,’ played a most important part in the history of early navigation. If once the trade-winds (the eastern Winds that blew just north of the tropics) had blown your ship into the Sargasso Sea, you were lost. At least, that is what the sailors of the Middle Ages firmly believed. Your vessel would find itself caught by miles and miles of solid seaweed and everyone on board would slowly perish through hunger and thirst, while the ghastly wreck would remain for ever bobbing up and down beneath the cloudless sky as a silent warning to others who might be tempted to defy the gods.

  When finally Columbus sailed placidly through the heart of this dullish stretch of water, it was shown that the fairy story about miles and miles of solid seaweed had been grossly exaggerated. But even to-day there is something mysterious and uncanny to most people in that name ‘Sargasso Sea.’ It sounds medieval. It smacks of one of Dante’s infernal circles. Actually, however, it is no more exciting than the duck pond in your park.

  But to return to the Gulf Stream. Part of the North Atlantic Eddy finally finds its way into the Caribbean Sea. There it is joined by a current that moves westward from the coast of Africa. These two currents, in addition to its own water, are too much for the Caribbean Sea. Like a cup that has been over-filled, the stream flows over into the Gulf of Mexico.

  THE GULF STREAM IN YOUR KITCHEN

  The Gulf of Mexico has not got room for all this additional water, and, using the straits between Florida and Cuba as a spigot, it pours forth a broad stream of hot water (80° Fahrenheit) which thereupon is called the Gulf Stream. When the Gulf Stream leaves the spigot it flows at the rate of five miles an hour, which is one of the reasons why the old sailing vessels gave it a wide berth whenever they could and preferred to make a lengthy detour rather than try to navigate against a current which so severely delayed their progress.

  From the Gulf of Mexico the Gulf Stream moves up northward, following the American coast until finally it is deflected by the shape of the eastern shore, when it begins its voyage across the north Atlantic. Just off the Grand Banks of Newfoundland it meets the so-called Labrador Current, which, coming fresh from the glacial regions of Greenland, is as cold and uninviting as the Gulf Stream is warm and hospitable. Out of the meeting of these two mighty currents arises that terrible fog which has given that part of the Atlantic such a dreadful reputation. It also accounts for the presence of those large numbers of icebergs which have played such a hideous part in the nautical history of the last fifty years. For, cut off by the summer’s sun from their solid Greenland moorings (those glaciers that still cover ninety per cent of that vast island), these bergs drift slowly southward until they are caught by the eddy caused by the meeting of the Gulf Stream and the Labrador Current.

  There they float around while they slowly melt. This melting process it is that makes them so dangerous, for only the tops remain visible while the ragged edges stay under water, just deep enough to cut through the hull of a ship as a knife cuts through butter. That whole region to-day is forbidden territory for all ocean liners, and it is constantly watched by United States patrol vessels (a special ice patrol, paid for by all nations) which blow up the smaller bergs and warn vessels of the presence of the bigger ones. Fishing boats, however, love this territory, for fishes which were born in the Arctic and were therefore accustomed to the cold temperature of the Labrador Current feel very unhappy in the tepid water of the Gulf Stream. While they are slowly making up their minds whether to go back to the Pole or try to swim across the warm Gulf Stream, they are caught by the nets of those French fishermen whose ancestors patronized the legendary Grand Banks of America hundreds of years before any one else. The two little islands of St Pierre and Miquelon, off the coast of Newfoundland, are the last remaining remnants of that vast French empire which two centuries ago covered the greater part of the North American continent.

  THE GULF STREAM

  As for the Gulf Stream, after leaving the so-called Cold Wall (produced by the difference in temperature between the Gulf stream and the Labrador Current) well to the north, it then leisurely moves across the Atlantic Ocean and spreads fan-wise over the coast of western Europe. Some of it turns southward and drifts along the coasts of Spain and Portugal. France and England and Ireland and Holland and Belgium and Denmark Mild the Scandinavian peninsula also benefit from a much milder temperature than they would otherwise enjoy. Having thus done its duty by humanity, this strange current, carrying more water than all the rivers of the world combined, withdraws discreetly into the Arctic Sea. This sea thereupon finds itself so full of aquatic substance that it must find relief by sending out a current of its own, that Greenland Current which in turn is responsible for that Labrador Current I have just described. But remember it is the air that is warmed by these currents that benefits these countries and not the current itself.

  It is a fascinating story.

  It is such a fascinating story that I am s
orely tempted to give far too much space to this chapter alone. But that I must not do.

  This chapter can only be a background—a general background of meteorology and oceanography and astronomy against which the actors in our play shall shortly act their part.

  Now let us drop the curtain for a second.

  When it rises the stage is set for a new act.

  That act will show you how men learned to find their way across those mountains and seas and deserts that had to be conquered ere we could truly call this world our home.

  The curtain rises again.

  Act II: Maps and methods of navigation.

  IF THE HIGHEST MOUNTAIN WOULD BE DUMPED INTO THE DEEPEST PART OF THE OCEAN!

  Explanation

  If we dumped the highest mountains of the world into the deepest part of the ocean (35,410 feet) situated between the Philippines and Japan, even Mount Everest would be more than 6,000 feet under water and the others in proportion. They are: 1. Everest (29,141); 2. Kinchinjinga, also in Asia, near Nepal (28,146); 3. Aconcagua in the Argentine (22,863); 4. Chimborazo in Ecuador (20,498); 5. McKinley in Alaska (20,300), the highest mountain In North America; 6. Kilima Njaro in Africa (19,321); 7. Logan In Canada (19,850); 8. Elbruz in the Caucasus (18,600); 9. Popocatepetl in Mexico (17,881); 10. Ararat in Armenia (16,925), the mountain on which Noah’s ark stranded; 11. Mont Blanc in the French Alps, the highest mountain in Europe (15,781); 12. Fujiyama in Japan (12,991). (Incidentally, there are twelve more mountains in the Himalayas which are higher than Aconcagua, but I do not mention them here because no one has ever heard of them.)

  The highest spot on which human beings live all the year is the village of Gartok (13) in Tibet (14,518). The highest lake is Titicaca (14) in Peru (12,466). The highest cities are (15) La Paz (11,800) and (16) Quito (9,343) in South America. The cloister of the Saint Bernard Pass (17) in Switzerland is the highest spot where people live all the year round in Europe (8,111); while Mexico City (18) is the highest town in North America (7,415). Finally there is the Dead Sea (19) in Palestine, which is 1,290 feet below sea-level.

  Chapter IV

  * * *

  MAPS: A VERY BRIEF CHAPTER UPON A VERY BIG AND FASCINATING SUBJECT: TOGETHER WITH A FEW OBSERVATIONS ON HOW PEOPLE SLOWLY LEARNED TO FIND THEIR WAY ABOUT ON THIS PLANET OF OURS

  We are so accustomed to maps that it is almost impossible for us to imagine a time when there were no maps, when the notion of travelling according to a map was as foreign to man’s conception of ultimate possibilities as the idea of traversing space in the form of a mathematical formula would be to us to-day.

  The ancient Babylonians, who were such excellent geometricians that they could make a cadastral survey of their entire kingdom (that survey was made in 3800 b.c., or 2400 years before Moses was born), have left us a few clay tablets containing what must have been an outline of their domains, but these were hardly maps in our sense of the word. The Egyptians, in order to get every penny of taxes they could sweat out of their hard-working subjects, also made a survey of their kingdom, which showed that they knew enough about practical mathematics to perform this difficult task. But no maps in the modern sense of the word have so far been found in any of the royal sepulchres.

  The Greeks, the most curious-minded and nosey people of the ancient world, wrote endless treatises upon the subject of geography, but we know next to nothing about their maps. Here and there in some great commercial centre there seem to have been engraved bronze tablets showing the best route to be followed if a merchant wanted to get from one part of the eastern Mediterranean to another. But none of these tablets has ever been dug up and we have no idea what they looked like. Alexander the Great, who covered greater distances than any other human being did before him and than many have done after him, must have been possessed of a certain ‘geographical sense,’ for he maintained a special body of professional ‘pacers’—men who went ahead of the army and kept an accurate account of the distances the indefatigable Macedonians wandered in their search for the gold of India. But of regular maps, which would have been understandable to ourselves, not a vestige, not a scrap, not a line.

  HOW MAP BECAME MAPS

  The Romans (the most marvellously organized ‘systematic plunderers’ of which the world has any account until the beginning of the great colonial epoch in Europe), who in quest of plunder went everywhere, lived everywhere, built roads everywhere, gathered taxes everywhere, hanged and crucified people everywhere, left the ruins of their temples and swimming-pools everywhere, seem to have been able to administer a world-empire without a single map worthy of the name. It is true their writers and orators quite frequently make mention of their maps and assure us that these were of remarkable accuracy and entirely dependable. But the only Roman map that has come down to us (if we except a small and insignificant piece of an ancient plan of Rome in the second century of our era) is something so primitive and clumsy that it is of no earthly value to modern man except as a historical curiosity.

  It is known to historians as the Peutinger map because it was a man called Conrad Peutinger, town clerk to the city of Augsburg, who first conceived the idea of having it broadcasted by means of the recently invented printing-presses of Johann Gutenberg of Strassburg. Unfortunately Peutinger did not have the original to work from. The manuscript map he used was a thirteenth-century copy of a third-century original, and during those thousand years rats and mice had made away with a great many important details.

  Even so, the general outline was undoubtedly that of the Roman original, and if that was the best the Romans could do they still had a great deal to learn. 1 will draw a copy of it here and let you judge for yourself. After a long and patient study of the document you will slowly begin to recognize what was in the mind of the Roman geographers. But you will also recognize that we have made enormous progress since the days when this spaghetti-shaped ‘world’ was the last word in travel literature for a Roman general bound for England or the Black Sea.

  A ROMAN MAP

  As for the maps of the Middle Ages, we can pass them by without any special comment. The road to Heaven was more important than the shortest route from the mouth of the Rhine to the mouth of the Danube, and maps became mere funny pictures, full of headless monsters (the poor Eskimos, huddled in their furs until their heads were no longer visible, were the originals for this fanciful notion) and snorting unicorns and spouting whales and hippogrifs and krakens and mermaids and griffons and all the other denizens of a world bewildered by fear and superstition. Jerusalem was of course shown as the centre of the world, and India and Spain were the ultimate limits, beyond which no man could hope to travel, and Scotland was a separate island, and the Tower of Babel was ten times as big as for entire city of Paris.

  Compared to these products of the medieval cartographers, the woven maps of the Polynesians (they look for all the world like something done by the children in a kindergarten, but they are exceedingly handy and very accurate) are veritable masterpieces of the navigator’s ingenuity. Not to mention the work of the Arabs, and of the Chinese, whose very existence, however, was hardly realized in medieval times. Nor was there any real improvement until the end of the fifteenth century.

  POLYNESIAN WOVEN MAP

  For then the Turks conquered the bridge-head connecting Europe with Asia, land traffic into the Orient was permanently interrupted, and it suddenly became necessary to find a new way to the Indies by the way of the open sea. That meant an end to the old familiar system of sailing by the church-towers of the nearest mainland or sailing by the sound of the dogs barking along the shore. And it was this necessity of finding one’s way across the ocean without seeing anything at all for weeks at a time except sky and water which brought about the great improvement in the navigating methods of that day.

  The Egyptians seem to have ventured as far as Crete but no further, and there was a constant interchange of commerce between the two peoples. The Cretans sent colonists to Palestine in the time of Rameses II.
The Phoenicians and the Greeks were ‘church-tower sailors’ at heart, although a few times they did quite remarkable things and even ventured as far as the Congo River and the Scilly Islands. Even then they undoubtedly hugged the shore as much as possible and at night pulled their boats up on dry land to escape being blown towards the open sea. As for the medieval merchants who navigated the Mediterranean, the North Sea, and the Baltic before the mariner’s compass was known to them, they were never for more than a few days without a glimpse of some distant mountain range.

  EROSION

  WIND

  MEDIEVAL MAP

  If they found themselves lost in the open, they had only one way in which to discover where the nearest land might be. For that purpose they always carried a few pigeons. They knew that pigeons would take the shortest route to the nearest bit of dry land. When they no longer knew what course to follow, they set one of their pigeons loose and observed the way it flew. Then they steered in that general direction taken by the bird until they saw the mountain tops and could make for the nearest harbour to ask where they might happen to be.

  Of course during the Middle Ages even the average person was more familiar with the stars than we are to-day. He had to be, because he lacked all sorts of information which nowadays comes to us in the printed form of almanacs and calendars. The more intelligent skippers therefore could find their way by studying the stars and by setting their course according to the Pole Star and the constellations. But in northern climes, where the sky was usually overcast, the stars were no great help. And navigation would have continued to be a painful and costly business of sailing by God and by guess (mostly the latter) if it had not been for the compass, which was in use in Europe about the middle of the thirteenth century. But the origin and the history of the compass are still shrouded in deep mystery, and what I tell you here is a matter of speculation rather than formal knowledge.