Lesson49
Rockets and artificial satellites can go far above the ionosphere, and even escape from the Earth. Yet they are complex and expensive, and in their present stage of development they cannot lift massive telescopes, keep them steady while the observations are being carried out, and then return them safely. Balloons are much easier to handle, and are also vastly cheaper. Their main limitation is that they are incapable of rising to the ionosphere. A height of between 80,000 and 90,000 feet is as much as can reasonably be expected, and so balloon-borne instruments can contribute little to either ultra-violet astronomy or X-ray astronomy. All the same, the balloon has much to be said in its favour, since it can at least carry heavy equipment above most of the atmospheric mass--thus eliminating blurring and unsteadiness of the images. Moreover, water-vapour and carbon dioxide in the lower air absorb most of the infra-red radiations sent to us from the planets. Balloon ascents overcome this hazard with ease.
Hot-air balloons date back to the year 1783, and within a few months of the first flight a French scientist, Charles, went up two miles in a free balloon. Yet there is little resemblance between these crude vehicles and a modern scientific balloon, which has by now become an important research tool.
The main development has been carried out by M. Schwarlschild and his team at Princeton University in the United States, in collaboration with the United States Navy, the National Science Foundation, and the National Aero-nautics and Space Administration. The 'Stratoscope' flights of 1959, concerned mainly with studies of the Sun, were remarkably successful, and the project has now been extended. With Stratoscope II, the overall height from the telescope to the top of the launch balloon is 666 feet, the balloons together weigh over two tons, and another two tons of ballast are carried for later release if height has be maintained during the night. The telescope, plus its controls weighs three-and-a-half tons. Two large parachutes arc also carried; in case of emergency, the instruments and their records can be separated from the main balloon system, and brought down gently. Many of the radio and electronic devices used are similar to those of artificial satellites.
Lesson50
In mediaeval times rivers were the veins of the body politic as well as economic. Boundaries between states or shires, they were crossed by fords which became the sites of towns, or by bridges which were often points of battle. Upon rivers the people of that time depended for food, power and transport.
In our day fish are caught in the sea and brought to us by rail and lorry; only the angler still thinks fresh-water fish important, and pollution of rivers drives him into smaller and smaller reaches in which to practise his sport. But in earlier times, when sea fish were eaten only by those who lived on the sea coast, when meat was obtainable only for part of the year, and when fasts were frequent and universally practised, river fish played an important part in the national life. Every abbey and great man's house had its fish pond, and across the rivers great and small stretched the fish weirs, usually made of stakes and nets or basket-work. Between the owners of the fisheries and the bargemaster who needed an unimpeded passage continuous war was fought, till the importance of fresh-water fish lessened as the practice of fasting ceased to be universal, as meat be-came available all the year round, and as the transport of sea fish inland became practicable.
Rivers were also the most important source of power. Every stream had its mills, not only for grinding corn, but for all the other industrial processes of the time, such as fulling* cloth or driving the hammers of ironworks. Placed down the bank wherever a head of water could be got, these mills were to be found on the tiny stream that ran through a village, or on the bigger river that was also used for navigation. An artificial cut was made from the river to bring the water at proper height to the water-wheel, and, in order to make sure of a supply of water at all seasons, the mill-owner usually built a weir across the river to hold back the water and so form an artificial reservoir. If the river were navigable, the centre of such a weir was made of planks held vertically by cross beams so that they could be removed when it was necessary to pass a barge, or was fitted with a single pair of gates. Such weirs were called staunches or flash-locks; they did not disappear from the bigger rivers till present times, and may still be seen in the Fens.
Lesson51
Two main techniques have been used for training elephants, which we may call respectively the tough and the gentle. The former method simply consists of setting an elephant to work and beating him until he does what is expected of him. Apart from any moral considerations this is a stupid method of training, for it produces a resentful animal who at a later stage may well turn man-killer. The gentle method requires more patience in the early stages, but produces a cheerful, good-tempered elephant who will give many years of loyal service.
The first essential in elephant training is to assign to the animal a single mahout who will be entirely responsible for the job. Elephants like to have one master just as dogs do, and are capable of a considerable degree of personal affection. There are even stories of half-trained elephant calves who have refused to feed and pined to death when by some unavoidable circumstance they have been deprived of their own trainer. Such extreme cases must probably be taken with a grain of salt, but they do underline the general principle that the relation-ship between elephant and mahout is the key to successful training.
The most economical age to capture an elephant for training is between fifteen and twenty years, for it is then almost ready to undertake heavy work and can begin to earn its keep straight away. But animals of this age do not easily become subservient to man, and a very firm hand must be employed in the early stages. The captive elephant, still roped to a tree, plunges and screams every time a man approaches, and for several days will probably refuse all food through anger and fear. Sometimes a tame elephant is tethered nearby to give the wild one confidence, and in most cases the captive gradually quietens down and begins to accept its food. The next stage is to get the elephant to the training establishment, a ticklish business which is achieved with the aid of two tame elephants roped to the captive on either side.
When several elephants are being trained at one time it is customary for the new arrival to be placed between the stalls of two captives whose training is already well advanced. It is then left completely undisturbed with plenty of food and water so that it can absorb the atmosphere of its new home and see that nothing particularly alarming is happening to its companions. When it is eating normally its own training begins. The trainer stands in front of the elephant holding a long stick with a sharp metal point. Two assistants, mounted or tame elephants, control the captive from either side, while others rub their hands over his skin to the accompaniment of a monotonous and soothing chant. This if supposed to induce pleasurable sensations in the elephant, and its effects are rein-forced by the use of endearing epithets, such as 'ho ! my son', or 'ho ! my father', or 'my mother', according to the age and sex of the captive. The elephant is not immediately susceptible to such blandishments, however, and usually lashes fiercely with its trunk in all directions. These movements are controlled by the trainer with the metal-pointed stick, and the trunk eventually becomes so sore that the elephant curls it up and seldom afterwards uses it for offensive purposes.
Lesson52
An earthquake comes like a thief in the night, without warning. It was necessary, therefore, to invent instruments that neither slumbered nor slept. Some devices were quite simple. one, for instance, consisted of rods of various lengths and thicknesses which would stand up on end like ninepins. when a shock came it shook the rigid table upon which these stood. If it were gentle, only the more unstable rods fell. If it were severe, they all fell. Thus the rods by falling, and by the direction in which they fell, recorded for the slumbering scientist the strength of a shock that was too weak to waken him and the direction from which it came.
But instruments far more delicate than that were needed if any really serious advance was to be made. The ideal to be aimed at was to devise an instrument that could record with a pen on paper the movements, of the ground or of the table, as the quake passed by. While I write my pen moves, but the paper keeps still. With practice, no doubt, I could in time learn to write by holding the still while the paper moved. That sounds a silly suggestion, but that was precisely the idea adopted in some of the early instruments (seismometers) for recording earthquake waves. But when table, penholder and paper are all moving how is it possible to write legibly? The key to a solution of that problem lay in an every- day observation. Why does a person standing in a bus or train tend to fall when a sudden start is made? It is because his feet move on, but his head stays still.A simple experiment will help us a little further. Tie a heavy weight at the end of a long piece of string. With the hand held high in the air hold the strings so that the weight nearly touches the ground. Now move the hand to and fro and around but not up and down. It will be found that the weight moves but slightly or not at all. Imagine a pen attached to the weight in such a way that its point rests upon a piece of paper on the floor. Imagine an earthquake shock shaking the floor, the paper, you and your hand. In the midst of all this movement the weight and the pen would be still. But as the paper moved from side to side under the pen point its movement would be recorded in ink upon its surface. It was upon this principle that the first instruments were made, but the paper was wrapped round a drum which rotated slowly. As long as all was still the pen drew a straight line, but while the drum was being shaken the line that the pen was drawing wriggled from side to side. The apparatus thus described, however, records only the horizontal component of the wave movement, which is, in fact, much more complicated. If we could actually see the path described by a particle, such as a sand grain in the rock, it would be more like that of a bluebottle buzzing round the room; it would be up and down, to and fro and from side to side. Instruments have been devised and can he so placed that all three elements can be recorded in different graphs.
When the instrument is situated at more than 700 miles from the earthquake centre, the graphic record shows three waves arriving one after the other at short intervals. The first records the arrival of longitudinal vibrations. The second marks the arrival of transverse vibrations which travel more slowly and arrive several minutes after the first. These two have travelled through the earth. It was from the study of these that so much was learnt about the interior of the earth. The third, or main wave, is the slowest and has travelled round the earth through the surface rocks.
Lesson53
The French Foreign Legion was founded by a Royal Ordinance, written on a small piece of official French War Office notepaper dated March 9th, 1831, and signed by the then reigning monarch of France, Louis-Philippe. He had been on the throne for barely eight months when he authorized this measure, which was as much a product of necessity as of careful planning, although there may be divided views on this.
The reasons for forming the French Foreign Legion were probably twofold. In the first place the men of the disbanded royal bodyguard and the Regiment of Hohenlohe, suddenly turned loose on to the street of a capital seething with un-rest, unemployed and perhaps disgruntled at their abrupt dismissal, were a potentially dangerous element. They were trained to the use of arms, and should they become tools of the politically ambitious or discontented they would present a distinct menace to the new regime, not yet too firmly established and sure of itself.
For some time Paris had been swarming with countless other discharged foreign soldiers who had served in the French army at various times under the Empire and the Republic, many of whom were in needy circumstances and open to suggestion, whilst others were openly looking for trouble and always ready to take part in any disturbance. It was clearly both expedient and desirable to re-move these dangers as far away from the capital as possible.
Next, the Algerian adventure had begun, and it appeared that this might prove expensive in lives. The more Frenchmen killed in North Africa, the less popular the government at home would be, so if foreign cannon fodder was available so much the better. The Algerian landing had been viewed with mixed feelings in a politically divided France, but there does not seem to have been, any marked indication on the part of the politicians that they were unanimous that the occupation should be abruptly terminated; most were wary and many apprehensive as to how the Algerian business would turn out.
The formation of a foreign legion seemed therefore to be an ideal method of killing these two birds with one stone. Once the conditions were made clear there does not seem o have been any serious opposition.
Marshal Soult was reputed to be the man behind the scheme both for removing and using the unemployed foreign ex-soldiers. He could not have failed to recognize, once they were formed into disciplined units, how useful they would be, both for garrison duty and for active operations in Algeria, nor the fact that if their casualties were heavy or their conditions not of the best, there would be no embarrassing reaction for agitation in France on their behalf.
The Royal Ordinance decreed that there should be a legion formed foreigners for service outside France, which was to be called the 'Foreign Legion' and it was to be part of the French army and under the control of the War Minister. It laid down that as far as possible companies should be composed of men of the same nationality or who spoke a common language. Algeria was not specificall y mentioned but as it was the only scrap of foreign territory of any size possessed by France at that moment, there was no doubt as to the meaning of the phrase 'outside France'.
In the anxiety to get dubious, restless characters out of the country no questions were asked as to nationality, previous record or history, and no proof of identity was required. The name and particulars given by the recruit were accepted at face value and many gave noms de guerre,* for understandable reasons. Thus the practice began, and the tradition started of 'asking no questions'. This tradition of guaranteeing anonymity began to develop quickly, although it was not until later that it was carried to the extreme of denying all knowledge of any individuals who were in its ranks and of refusing point blank to answer questions or to allow any outside contact with the legionnaires.
Lesson54
We must conclude from the work of those who have studied the origin of life, that given a planet only approximately like our own, life is almost certain to start. Of all the planets in our own solar system we arc now pretty certain the Earth is the only one on which life can survive. Mars is too dry and poor in oxygen, Venus far too hot, and so is Mercury, and the outer planets have temperatures near absolute zero and hydrogen-dominated atmospheres. But other suns, stars as the astronomers call them, are bound to have planets like our own, and as the number of stars in the universe is so vast, this possibility becomes virtual certainty. There are one hundred thousand million stars in our own Milky Way alone, and then there are three thousand million other Milky Ways, or Galaxies, in the universe. So the number of stars that we know exist is estimated at about 300 million million million.
Although perhaps only 1 per cent of the life that has started somewhere will develop into highly complex and intelligent patterns, so vast is the number of planets that intelligent life is bound to be a natural part of the universe.
If then we are so certain that other intelligent life exists in the universe, why have we had no visitors from outer space yet ? First of all, they may have come to this planet of ours thousands or millions of years ago, and found our then prevailing primitive state completely uninteresting to their own advanced knowledge. Professor Ronald Bracewell, a leading American radio-astronomer, argued in Nature that such a superior civilization, on a visit to our own solar system, may- have left an automatic messenger behind to await the possible awakening of an advanced civilization. Such a messenger, receiving our radio and television signals, might well re-transmit them back to its home-planet, although what impression any other civilization would thus get from us is best left unsaid.
But here we come up against the most difficult of all obstacles to contact with people on other planets--the astronomical distances which separate us. As a reasonable guess, they might, on an average, be 100 light years away. (A light year is the distance which light travels at 186,000 miles per second in one year, namely 6 million million miles.) Radio waves also travel at the speed of light, and assuming such an automatic messenger picked up our first broadcasts of the 1920's, the message to its home planet is barely halfway there. Similarly, our own Present primitive chemical rockets, though good enough to orbit men, have no chance of transporting us to the nearest other star, four light years away, let alone distances of tens or hundreds of light years.
Fortunately, there is a 'uniquely rational way' for us to communicate with other intelligent beings, as Walter Sullivan has put it in his excellent recent book, We are not alone. This depends on the precise radio-frequency of the 21-cm wavelength, or 1420 megacycles per second. It is the natural frequency of emission of the hydrogen atoms in space and was discovered by us in 1951; it must be known to any kind of radio-astronomer in the universe.
Once the existence of this wave-length had been discovered, it was not long before its use as the uniquely recognizable broadcasting frequency for interstellar communication was suggested. Without something of this kind, searching for intelligences on other planets would be like trying to meet a friend in London without a Pre-arranged rendezvous and absurdly wandering the streets in the hope of a chance encounter.