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These wonderful nitrogen-absorbing bacteria do not appear in all soil, although they are very widely distributed. So far as known they form nodules only on the roots of a few species of plants. In their original form in the soil they are neutral – that is, not especially adapted to beans, or peas, or any one particular kind of crop. But if clover, for instance, is planted, they straightway form nodules and become especially adapted to the clover plant, so that, as every farmer knows, the second crop of clover on worn-out land is much better than the first. And, curiously enough, when once the bacteria have become thoroughly adapted to one of the crops, say beans, they will not affect peas or clover, or only feebly.
Another strange feature of the life of these little creatures, which has a marvellous suggestion of intelligence, is their activities in various kinds of soil. When the ground is very rich – that is, when it contains plenty of nitrogenous matter – they are what Professor Nobbe calls "lazy." They do not readily form nodules on the roots of the plants, seeming almost to know that there is no necessity for it. But when once the nitrogenous matter in the soil begins to fail, then they work more sharply, and when it has gone altogether they are at the very height of activity. Consequently, unless the soil is really worn out, or very poor to begin with, there is no use in inoculating it – it would be like "taking owls to Athens," as Professor Nobbe says.
Having thus proved the remarkable efficacy of soil inoculation in his laboratory and greenhouses, where I saw great numbers of experiments still going forward, Professor Nobbe set himself to make his discoveries of practical value. He gave to his bacteria cultures the name "Nitragen" – spelled with an "a" – and he produced separate cultures for each of the important crops – peas, beans, vetch, lupin, and clover. In 1894 the first of these were placed on the market, and they have had a steadily increasing sale, although such a radical innovation as this, so far out of the ordinary run of agricultural operation, and so almost unbelievably wonderful, cannot be expected to spread very rapidly. The cultures are now manufactured at one of the great commercial chemical laboratories on the river Main. I saw some of them in Professor Nobbe's laboratory. They come in small glass bottles, each marked with the name of the crop for which it is especially adapted. The bottle is partly filled with the yellow gelatinous substance in which the bacteria grow. On the surface of this there is a mossy-like growth, resembling mould. This consists of innumerable millions of the little oblong bacteria. A bottle costs about fifty cents and contains enough bacteria for inoculating half an acre of land. It must be used within a certain number of weeks after it is obtained, while it is still fresh. The method of applying it is very simple. The contents of the bottle are diluted with warm water. Then the seeds of the beans, clover, or peas, which have previously been mixed with a little soil, are treated with this solution and thoroughly mixed with the soil. After that the mass is partially dried so that the seeds may be readily sown. The bacteria at once begin to propagate in the soil, which is their natural home, and by the time the beans or peas have put out roots they are present in vast numbers and ready to begin the active work of forming nodules. It is not known exactly how the bacteria absorb the free nitrogen from the air, but they do it successfully, and that is the main thing. Many German farmers have tried Nitragen. One, who was sceptical of its virtues, wrote to Professor Nobbe that he sowed the bacteria-inoculated seeds in the form of a huge letter N in the midst of his field, planting the rest in the ordinary way. Before a month had passed that N showed up green and big over all the field, the plants composing it being so much larger and healthier than those around it.
The United States Government has recently been experimenting along the same lines and has produced a new form of dry preparation of the bacteria in some cakes somewhat resembling a yeast-cake.
The possibilities of such a discovery as this seem almost limitless. Science predicts the exhaustion of nitrogen and consequent failure of the food supply, and science promptly finds a way of making plants draw nitrogen from the boundless supplies of the air. The time may come when every farmer will send for his bottles or cakes of bacteria culture every spring as regularly as he sends for his seed, and when the work of inoculating the soil will be a familiar agricultural process, with discussions in the farmers' papers as to whether two bottles or one is best for a field of sandy loam with a southern exposure. Stranger things have happened. But it must be remembered, also, that the work is in its infancy as yet, and that there are vast unexplored fields and innumerable possibilities yet to fathom.
Wonderful as this discovery is, and much as it promises in the future, its efficacy, as soon as it becomes generally known, is certain to be overestimated, as all new discoveries are. Professor Nobbe himself says that it has its own limited serviceability. It will produce a bounteous crop of beans in the pure sand of the sea-shore if (and this is an important if) that sand also contains enough of the mineral substances – phosphorus, potassium, and so on – and if it is kept properly watered. A man with a worn-out farm cannot go ahead blindly and inoculate his soil and expect certain results. He must know the exact disease from which his land is suffering before he applies the remedy. If it is deficient in the phosphates, bacteria cultures will not help it, whereas if it is deficient in nitrogen, bacteria are just what it needs. And so agricultural education must go hand in hand with the introduction of these future preservers of the human race. It is safe to say that by the time there is a serious failure of the earth's soil for lack of nitrogen, science, with this wonderful beginning, will have ready a new system of cultivation, which will gradually, easily, and perfectly take the place of the old.
Before leaving this wonderful subject of soil inoculation, a word about Professor Nobbe himself will surely be of interest. I visited his laboratory and saw his experiments.
Tharandt, in Saxony, where Professor Nobbe has carried on his investigations for over thirty years, is a little village set picturesquely among the Saxon hills, about half an hour's ride by railroad from the city of Dresden. Here is located the Forest Academy of the Kingdom, with which Professor Nobbe is prominently connected, and here also is the agricultural experiment station of which he is director. He has been for more than forty years the editor of one of the most important scientific publications in Germany; he is chairman of the Imperial Society of Agricultural Station Directors, and he has been the recipient of many honours.
We now come to a consideration of the other method – the fixing of nitrogen by machinery: a practical problem for the inventor.
Every one has noticed the peculiar fresh smell of the air which follows a thunderstorm; the same pungent odour appears in the vicinity of a frictional electric machine when in operation. This smell has been attributed to ozone, but it is now thought that it may be due to oxides of nitrogen; in other words, the electric discharges of lightning or of the frictional machine have burned the air – that is, combined the nitrogen and oxygen of the air, forming oxides of nitrogen.
The fact that an electric spark will thus form an oxide of nitrogen has long been known, but it remained for two American inventors, Mr. Charles S. Bradley and Mr. D. R. Lovejoy, of Niagara Falls, N. Y., to work out a way by inventive genius for applying this scientific fact to a practical purpose, thereby originating a great new industry. I shall not attempt here to describe the long process of experimentation which led up to the success of their enterprise. Here was their raw material all around them in the air; their problem was to produce a large number of very hot electric flames in a confined space or box so that air could be passed through, rapidly burned, and converted into oxides of nitrogen (nitric oxides and peroxides), which could afterward be collected. They took the power supplied by the great turbine wheels at Niagara Falls and produced a current of 10,000 volts, a pressure far above anything ever used before for practical purposes in this country. This was led into a box or chamber of metal six feet high and three feet in diameter – the box having openings to admit the air. By means of a revolving cylinder the electric current is made to produce a rapid continuance of very brilliant arcs, exactly like the glaring white arc of the arc-lamp, only much more intense, a great deal hotter. The air driven in through and around these hot arcs is at once burned, combining the oxygen and nitrogen of which it is composed and producing the desired oxides of nitrogen. These are led along to a chamber where they are combined with water, producing nitric or nitrous acid; or if the gases are brought into contact with caustic potash, saltpetre is the result; if with caustic soda, nitrate of soda is the product – a very valuable fertiliser. And the inventors have been able to produce these various results at an expense so low that they can sell their output at a profit in competition with nitrates from other sources, thus giving the world a new source of fertiliser at a moderate price.
In this way the power of Niagara has become a factor in the food question, a defence against the ultimate hunger of the human race. And when we think of the hundreds of other great waterfalls to be utilised, and with our growing knowledge of electricity this utilisation will become steadily cheaper, easier, it would seem that the inventor had already found a way to help the farmer. Then there is the boundless power of the tides going to waste, of the direct rays of the sun utilised by some such sun motor as that described in another chapter of this book, which in time may be called to operate upon the boundless reservoir of nitrogen in the air for helping to produce the future food for the human race.
CHAPTER VII
MARCONI AND HIS GREAT ACHIEVEMENTS
New Experiments in Wireless Telegraphy
No invention of modern times, perhaps, comes so near to being what we call a miracle as the new system of telegraphy without wires. The very thought of communicating across the hundreds of miles of blue ocean between Europe and America with no connection, no wires, nothing but air, sunshine, space, is almost inconceivably wonderful. A few years ago the mere suggestion of such a thing would have been set down as the wildest flight of imagination, unbelievable, perfectly impossible. And yet it has come to pass!
Think for a moment of sitting here on the shore of America and quietly listening to words sent through space across some 3,000 miles of ocean from the edge of Europe! A cable, marvellous as it is, maintains a real connection between speaker and hearer. We feel that it is a road along which our speech can travel; we can grasp its meaning. But in telegraphing without wires we have nothing but space, poles with pendent wires on one side of the broad, curving ocean, and similar poles and wires (or perhaps only a kite struggling in the air) on the other – and thought passing between!
I have told in the first "Boys' Book of Inventions" of Guglielmo Marconi's early experiments. That was a chapter of uncertain beginnings, of great hopes, of prophecy. This is the sequel, a chapter of achievement and success. What was only a scientific and inventive novelty a few years ago has become a great practical enterprise, giving promise of changing the whole world of men, drawing nations more closely together, making us near neighbours to the English and the Germans and the French – in short, shrinking our earth. There may come a time when we will think no more of sending a Marconigram, or an etheragram, or whatever is to be the name of the message by wireless telegraphy, to an acquaintance in England than we now think of calling up our neighbour on the telephone.
Every one will recall the astonishment that swept over the country in December, 1901, when there came the first meagre reports of Marconi's success in telegraphing across the Atlantic Ocean between England and Newfoundland. At first few would believe the reports, but when Thomas A. Edison, Graham Bell, and other great inventors and scientists had expressed their confidence in Marconi's achievement, the whole country, was ready to hail the young inventor with honours. And his successes since those December days have been so pronounced – for he had now sent messages both ways across the Atlantic and at much greater distances – have more than borne out the promise then made. Wireless telegrams can now be sent directly from the shore of Massachusetts to England, and ocean-going ships are being rapidly equipped with the Marconi apparatus so that they can keep in direct communication with both continents during every day of the voyage. On some of the great ships a little newspaper is published, giving the world's news as received from day to day.
It was the good fortune of the writer to arrive in St. John's, Newfoundland, during Mr. Marconi's experiments in December, 1901, only a short time after the famous first message across the Atlantic had been received. Three months later it was also the writer's privilege to visit the Marconi station at Poldhu, in Cornwall, England, from which the message had been sent, Mr. Marconi being then planning his greater work of placing his invention on a practical basis so that his company could enter the field of commercial telegraphy. It was the writer's fortune to have many talks with Mr. Marconi, both in America and in England, to see him at his experiments, and to write some of the earliest accounts of his successes. The story here told is the result of these talks.
Mr. Marconi kept his own counsel regarding his plans in coming to Newfoundland in December, 1901. He told nobody, except his assistants, that he was going to attempt the great feat of communicating across the Atlantic Ocean. Though feeling very certain of success, he knew that the world would not believe him, would perhaps only laugh at him for his great plans. The project was entirely too daring for public announcement. Something might happen, some accident to the apparatus, that would cause a delay; people would call this failure, and it would be more difficult another time to get any one to put confidence in the work. So Marconi very wisely held his peace, only announcing what he had done when success was assured.
Mr. Marconi landed at St. John's, Newfoundland, on December 6, 1901, with his two assistants, Mr. Kemp and Mr. Paget.
He set up his instruments in a low room of the old barracks on Signal Hill, which stands sentinel at the harbour mouth half a mile from the city of St. John's. So simple and easily arranged is the apparatus that in three days' time the inventor was prepared to begin his experiments. On Wednesday, the 11th, as a preliminary test of the wind velocity, he sent up one of his kites, a huge hexagonal affair of bamboo and silk nine feet high, built on the Baden-Powell model: the wind promptly snapped the wire and blew the kite out to sea. He then filled a 14-foot hydrogen balloon, and sent it upward through a thick fog bank. Hardly had it reached the limit of its tetherings, however, when the aërial wire on which he had depended for receiving his messages fell to the earth, the balloon broke away, and was never seen again. On Thursday, the 12th, a day destined to be important in the annals of invention, Marconi tried another kite, and though the weather was so blustery that it required the combined strength of the inventor and his assistants to manage the tetherings, they succeeded in holding the kite at an elevation of about 400 feet. Marconi was now prepared for the crucial test. Before leaving England he had given detailed instructions to his assistants for the transmission of a certain signal, the Morse telegraphic S, represented by three dots (…), at a fixed time each day, beginning as soon as they received word that everything at St. John's was in readiness. This signal was to be clicked out on the transmitting instruments near Poldhu, Cornwall, the southwestern tip of England, and radiated from a number of aërial wires pendent from masts 210 feet high. If the inventor could receive on his kite-wire in Newfoundland some of the electrical waves thus produced, he knew that he held the solution of the problem of transoceanic wireless telegraphy. He had cabled his assistants to begin sending the signals at three o'clock in the afternoon, English time, continuing until six o'clock; that is, from about 11.30 to 2.30 o'clock in St. John's.
At noon on Thursday (December 12, 1901) Marconi sat waiting, a telephone receiver at his ear, in a room of the old barracks on Signal Hill. To him it must have been a moment of painful stress and expectation. Arranged on the table before him, all its parts within easy reach of his hand, was the delicate receiving instrument, the supreme product of years of the inventor's life, now to be submitted to a decisive test. A wire ran out through the window, thence to a pole, thence upward to the kite which could be seen swaying high overhead. It was a bluff, raw day; at the base of the cliff 300 feet below thundered a cold sea; oceanward through the mist rose dimly the rude outlines of Cape Spear, the easternmost reach of the North American Continent. Beyond that rolled the unbroken ocean, nearly 2,000 miles to the coast of the British Isles. Across the harbour the city of St. John's lay on its hillside wrapped in fog: no one had taken enough interest in the experiments to come up here through the snow to Signal Hill. Even the ubiquitous reporter was absent. In Cabot Tower, near at hand, the old signalman stood looking out to sea, watching for ships, and little dreaming of the mysterious messages coming that way from England. Standing on that bleak hill and gazing out over the waste of water to the eastward, one finds it difficult indeed to realise that this wonder could have become a reality. The faith of the inventor in his creation, in the kite-wire, and in the instruments which had grown under his hand, was unshaken.
"I believed from the first," he told me, "that I would be successful in getting signals across the Atlantic."
Only two persons were present that Thursday noon in the room where the instruments were set up – Mr. Marconi and Mr. Kemp. Everything had been done that could be done. The receiving apparatus was of unusual sensitiveness, so that it would catch even the faintest evidence of the signals. A telephone receiver, which is no part of the ordinary instrument, had been supplied, so that the slightest clicking of the dots might be conveyed to the inventor's ear. For nearly half an hour not a sound broke the silence of the room. Then quite suddenly Mr. Kemp heard the sharp click of the tapper as it struck against the coherer; this, of course, was not the signal, yet it was an indication that something was coming. The inventor's face showed no evidence of excitement. Presently he said:
"See if you can hear anything, Kemp."
Mr. Kemp took the receiver, and a moment later, faintly and yet distinctly and unmistakably, came the three little clicks – the dots of the letter S, tapped out an instant before in England. At ten minutes past one, more signals came, and both Mr. Marconi and Mr. Kemp assured themselves again and again that there could be no mistake. During this time the kite gyrated so wildly in the air that the receiving wire was not maintained at the same height, as it should have been; but again, at twenty minutes after two, other repetitions of the signal were received.
Thus the problem was solved. One of the great wonders of science had been wrought. But the inventor went down the hill toward the city, now bright with lights, feeling depressed and disheartened – the rebound from the stress of the preceding days. On the following afternoon, Friday, he succeeded in getting other repetitions of the signal from England, but on Saturday, though he made an effort, he was unable to hear anything. The signals were, of course, sent continuously, but the inventor was unable to obtain continuous results, owing, as he explains, to the fluctuations of the height of the kite as it was blown about by the wind, and to the extreme delicacy of his instruments, which required constant adjustment during the experiments.
Even now that he had been successful, the inventor hesitated to make his achievement public, lest it seem too extraordinary for belief. Finally, after withholding the great news for two days, certainly an evidence of self-restraint, he gave out a statement to the press, and on Sunday morning the world knew and doubted; on Monday it knew more and believed. Many, like Mr. Edison, awaited the inventor's signed announcement before they would credit the news. Sir Cavendish Boyle, the Governor of Newfoundland, reported at once to King Edward; and the cable company which has exclusive rights in Newfoundland, alarmed at an achievement which threatened the very existence of its business, demanded that he desist from further experiments within its territory, truly an evidence of the belief of practical men in the future commercial importance of the invention. It is not a little significant of the increased willingness of the world, born of expanding knowledge, to accept a new scientific wonder, that Mr. Marconi's announcement should have been so eagerly and so generally believed, and that the popular imagination should have been so fired with its possibilities. One cannot but recall the struggle against doubt, prejudice, and disbelief in which the promoters of the first transatlantic cable were forced to engage. Even after the first cable was laid (in 1858), and messages had actually been transmitted, there were many who denied that it had ever been successfully operated, and would hardly be convinced even by the affidavits of those concerned in the work. But in the years since then, Edison, Bell, Röntgen, and many other famous inventors and scientists have taught the world to be chary of its disbelief. Outside of this general disposition to friendliness, however, Marconi on his own part had well earned the credit of the careful and conservative scientist; his previous successes made it the more easy to credit his new achievement. For, as an Englishman (Mr. Flood Page), in defending Mr. Marconi's announcement, has pointed out, the inventor has never made any statement in public until he has been absolutely certain of the fact; he has never had to withdraw any statement that he has made as to his progress in the past. And these facts unquestionably carried great weight in convincing Mr. Edison, Mr. Graham Bell, and others of equal note of the literal truth of his report. It was astonishing how overwhelmingly credit came from every quarter of the world, from high and low alike, from inventors, scientists, statesmen, royalty. Before Marconi left St. John's he was already in receipt of a large mail – the inevitable letters of those who would offer congratulations, give advice, or ask favours. He received offers to lecture, to write articles, to visit this, that, and the other place – and all within a week after the news of his success. The people of the "ancient colony" of Newfoundland, famed for their hospitality, crowned him with every honour in their power. I accompanied Mr. Marconi across the island on his way to Nova Scotia, and it seemed as if every fisher and farmer in that wild country had heard of him, for when the train stopped they came crowding to look in at the window. From the comments I heard, they wondered most at the inventor's youthful appearance. Though he was only twenty-seven years old, his experience as an inventor covered many years, for he began experimenting in wireless telegraphy before he was twenty. At twenty-two he came to London from his Italian home, and convinced the British Post-Office Department that he had an important idea; at twenty-three he was famous the world over.
Following this epoch-making success Mr. Marconi returned to England, where he continued most vigorously the work of perfecting his invention, installing more powerful transmitters, devising new receivers, all the time with the intention of following up his Newfoundland experiments with the inauguration of a complete system of wireless transmission between America and Europe. In the latter part of the year 1902 he succeeded in opening regular communication between Nova Scotia and England, and January 18, 1903, marked another epoch in his work. On that day there was sent by Marconi himself from the wireless station at South Wellfleet, Cape Cod, Mass., to the station at Poldhu, Cornwall, England, a distance of 3,000 miles, the message – destined to be historic – from the President of the United States to the King of England.
It will be interesting to know something of the inventor himself. He is somewhat above medium height, and, though of a highly strung temperament, he is deliberate in his movements. Unlike the inventor of tradition, he dresses with scrupulous neatness, and, in spite of being a prodigious worker, he finds time to enjoy a limited amount of club and social life. The portrait published with this chapter, taken at St. John's a few days after the experiments, gives a very good idea of the inventor's face, though it cannot convey the peculiar lustre of his eyes when he is interested or excited – and perhaps it makes him look older than he really is. One of the first and strongest impressions that the man conveys is that of intense nervous activity and mental absorption; he has a way of pouncing upon a knotty question as if he could not wait to solve it. He talks little, is straightforward and unassuming, submitting good-naturedly, although with evident unwillingness, to being lionised. In his public addresses he has been clear and sensible; he has never written for any publication; nor has he engaged in scientific disputes, and even when violently attacked he has let his work prove his point. And he has accepted his success with calmness, almost unconcern; he certainly expected it. The only elation I saw him express was over the attack of the cable monopoly in Newfoundland, which he regarded as the greatest tribute that could have been paid his achievement. During all his life, opposition has been his keenest spur to greater effort.
Though he was born and educated in Italy, his mother was of British birth, and he speaks English as perfectly as he does Italian. Indeed, his blue eyes, light hair, and fair complexion give him decidedly the appearance of an Englishman, so that a stranger meeting him for the first time would never suspect his Italian parentage. His parents are still living, spending part of their time on their estate in Italy and part of the time in London. One of the first messages conveying the news of his success at St. John's went to them. He embarked in experimental research because he loved it, and no amount of honour or money tempts him from the pursuit of the great things in electricity which he sees before him. Besides being an inventor, he is also a shrewd business man, with a clear appreciation of the value of his inventions and of their possibilities when generally introduced. What is more, he knows how to go about the task of introducing them.
No sooner had Marconi announced the success of his Newfoundland experiments than critics began to raise objections. Might not the signals which he received have been sent from some passing ship fitted with wireless-telegraphy apparatus? Or, might they not have been the result of electrical disturbances in the atmosphere? Or, granting his ability to communicate across seas, how could he preserve the secrecy of his messages? If they were transmitted into space, why was it not possible for any one with a receiving instrument to take them? And was not his system of transmission too slow to make it useful, or was it not rendered uncertain by storms? And so on indefinitely. An acquaintance with some of the principles which Marconi considers fundamental, and on which his work has been based, will help to clear away these objections and give some conception of the real meaning and importance of the work at St. John's and of the plans for the future development of the inventor's system.
In the first place, Mr. Marconi makes no claim to being the first to experiment along the lines which led to wireless telegraphy, or the first to signal for short distances without wires. He is prompt with his acknowledgment to other workers in his field, and to his assistants. Professor S. F. B. Morse, the inventor of telegraphy; Dr. Oliver Lodge and Sir William Preece, of England; Edison, Tesla, and Professors Trowbridge and Dolbear, of America, and others had experimented along these lines, but it remained for Marconi to perfect a system and put it into practical working order. He took the coherer of Branley and Calzecchi, the oscillator of Righi, he used the discoveries of Henry and Hertz, but his creation, like that of the poet who gathers the words of men in a perfect lyric, was none the less brilliant and original.
In its bare outlines, Marconi's system of telegraphy consists in setting in motion, by means of his transmitter, certain electric waves which, passing through the ether, are received on a distant wire suspended from a kite or mast, and registered on his receiving apparatus. The ether is a mysterious, unseen, colourless, odourless, inconceivably rarefied something which is supposed to fill all space. It has been compared to a jelly in which the stars and planets are set like cherries. About all we know of it is that it has waves – that the jelly may be made to vibrate in various ways. Etheric vibrations of certain kinds give light; other kinds give heat; others electricity. Experiments have shown that if the ether vibrates at the inconceivable swiftness of 400 billions of waves a second we see the colour red, if twice as fast we see violet, if more slowly – perhaps 230 millions to the second, and less – we have the Hertz waves used by Marconi in his wireless-telegraphy experiments. Ether waves should not be confounded with air waves. Sound is a result of the vibration of the air; if we had ether and no air, we should still see light, feel heat, and have electrical phenomena, but no sound would ever come to our ears. Air is sluggish beside ether, and sound waves are very slow compared with ether waves. During a storm the ether brings the flash of the lightning before the air brings the sound of thunder, as every one knows.
