Boys' Second Book of Inventions

But, unfortunately, most plants are unable to take up nitrogen in its gaseous form as it appears in the air. It must be combined with hydrogen in the form of ammonia or in some nitrate. Ammonia and the nitrates are, therefore, the basis of all fertilisers.

Now, the problem for the scientist and inventor takes this form: Here is the vast store-house of life-giving nitrogen in the air; how can it be caught, fixed, reduced to the purpose of men, spread on the hungry wheat-fields? The problem, therefore, is that of "fixing" the nitrogen, taking the gas out of the air and reducing it to a form in which it can be handled and used.

Two principal methods for doing this have already been devised, both of which are of fascinating interest. One of these ways, that of a clever American inventor, is purely a machinery process, the utilisation of power by means of which the nitrogen is literally sucked out of the air and combined with soda so that it produces nitrate of soda, a high-class fertiliser. The water power of Niagara Falls is used to do this work – it seems odd enough that Niagara should be used for food production!

The other method, that of a hard-working German professor, is the cunning utilisation of one of nature's marvellous processes of taking the nitrogen from the air and depositing it in the soil – for nature has its own beautiful way of doing it. I will describe the second method first because it will help to clear up the whole subject and lead up to the work of the American inventor and his extraordinary machinery.

Nearly every farmer, without knowing it, employs nature's method of fixing nitrogen every year. It is a simple process which he has learned from experience. He knows that when land is worn out by overcropping with wheat or other products which draw heavily on the earth's nitrogen supply certain crops will still grow luxuriantly upon the worn-out land, and that if these crops are left and ploughed in, the fertility of the soil will be restored, and it will again produce large yields of wheat and other nitrogen-demanding plants. These restorative crops are clover, lupin, and other leguminous plants, including beans and peas. Every one who is at all familiar with farming operations has heard of seeding down an old field to clover and then ploughing in the crop, usually in the second year.

The great importance of this bit of the wisdom of experience was not appreciated by science for many years. Then several German experimenters began to ask why clover and lupin and beans should flourish on worn-out land when other crops failed. All of these plants are especially rich in nitrogen, and yet they grew well on soil which had been robbed of its nitrogen. Why was this so?

It was a hard problem to solve, but science was undaunted. Botanists had already discovered that the roots of the leguminous plants – that is, clover, lupin, beans, peas, and so on – were usually covered with small round swellings, or tumors, to which were given the name nodules. The exact purpose of these swellings being unknown, they were set down as a condition, possibly, of disease, and no further attention was paid to them until Professor Hellriegel, of Burnburg, in Anhalt, Germany, took up the work. After much experimenting, he made the important discovery that lupins which had nodules would grow in soil devoid of nitrogen, and that lupins which had no nodules would not grow in the same soil. It was plain, therefore, that the nodules must play an important, though mysterious, part in enabling the plant to utilise the free nitrogen of the air. That was early in the '80s. His discovery at once started other investigators to work, and it was not long before the announcement came – and it came, curiously enough, at a time when Dr. Koch was making his greatest contributions to the world's knowledge of the germ theory of disease – that these nodules were the result of minute bacteria found in the soil. Professor Beyerinck, of Münster, gave the bacteria the name Radiocola.

It was at this time that Professor Nobbe took up the work with vigour. If these nodules were produced by bacteria, he argued that the bacteria must be present in the soil; and if they were not present, would it not be possible to supply them by artificial means? In other words, if soil, say worn-out farm-soil or, indeed, pure sand like that of the sea-shore could thus be inoculated, as a physician inoculates a guinea-pig with diphtheria germs, would not beans and peas planted there form nodules and draw their nourishment from the air? It was a somewhat startling idea, but all radically new ideas are startling; and, after thinking it over, Professor Nobbe began, in 1888, a series of most remarkable experiments, having as their purpose the discovery of a practical method of soil inoculation. He gathered the nodule-covered roots of beans and peas, dried and crushed them, and made an extract of them in water. Then he prepared a gelatine solution with a little sugar, asparagine, and other materials, and added the nodule-extract. In this medium colonies of bacteria at once began to grow – bacteria of many kinds. Professor Nobbe separated the Radiocola – which are oblong in shape – and made what is known as a "clear culture," that is, a culture in gelatine, consisting of billions of these particular germs, and no others. When he had succeeded in producing these clear cultures he was ready for his actual experiments in growing plants. He took a quantity of pure sand, and, in order to be sure that it contained no nitrogen or bacteria in any form, he heated it at a high temperature three different times for six hours, thereby completely sterilising it. This sand he placed in three jars. To each of these he added a small quantity of mineral food – the required phosphorus, potassium, iron, sulphur, and so on. To the first he supplied no nitrogen at all in any form; the second he fertilised with saltpetre, which is largely composed of nitrogen in a form in which plants may readily absorb it through their roots; the third of the jars he inoculated with some of his bacteria culture. Then he planted beans in all three jars, and awaited the results, as may be imagined, somewhat anxiously. Perfectly pure sterilised water was supplied to each jar in equal amounts and the seeds sprouted, and for a week the young shoots in the three jars were almost identical in appearance. But soon after that there was a gradual but striking change. The beans in the first jar, having no nitrogen and no inoculation, turned pale and refused to grow, finally dying down completely, starved for want of nitrogenous food, exactly as a man would starve for the lack of the same kind of nourishment. The beans in the second jar, with the fertilised soil, grew about as they would in the garden, all of the nourishment having been artificially supplied. But the third jar, which had been jealously watched, showed really a miracle of growth. It must be remembered that the soil in this jar was as absolutely free of nitrogen as the soil in the first jar, and yet the beans flourished greatly, and when some of the plants were analysed they were found to be rich in nitrogen. Nodules had formed on the roots of the beans in the third or inoculated jar only, thereby proving beyond the hope of the experimenter that soil inoculation was a possibility, at least in the laboratory.

With this favourable beginning Professor Nobbe went forward with his experiments with renewed vigour. He tried inoculating the soil for peas, clover, lupin, vetch, acacia, robinia, and so on, and in every case the roots formed nodules, and although there was absolutely no nitrogen in the soil, the plants invariably flourished. Then Professor Nobbe tried great numbers of difficult test experiments, such as inoculating the soil with clover bacteria and then planting it with beans or peas, or vice versa, to see whether the bacteria from the nodules of any one leguminous plant could be used for all or any of the others. He also tried successive cultures; that is, bean bacteria for beans for several years, to see if better results could be obtained by continued use. Even an outline description of all the experiments which Professor Nobbe made in the course of these investigations would fill a small volume, and it will be best to set down here only his general conclusions.

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.

Electricity is, indeed, only another name for certain vibrations in the ether. We say that electricity "flows" in a wire, but nothing really passes except an etheric wave, for the atoms composing the wire, as well as the air and the earth, and even the hardest substances, are all afloat in ether. Vibrations, therefore, started at one end of the wire travel to the other. Throw a stone into a quiet pond. Instantly waves are formed which spread out in every direction; the water does not move, except up and down, yet the wave passes onward indefinitely. Electric waves cannot be seen, but electricians have learned how to incite them, to a certain extent how to control them, and have devised cunning instruments which register their presence.

Electrical waves have long been harnessed by the use of wires for sending communications; in other words, we have had wire telegraphy. But the ether exists outside of the wire as well as within; therefore, having the ether everywhere, it must be possible to produce waves in it which will pass anywhere, as well through mountains as over seas, and if these waves can be controlled they will evidently convey messages as easily and as certainly as the ether within wires. So argued Mr. Marconi. The difficulty lay in making an instrument which would produce a peculiar kind of wave, and in receiving and registering this wave in a second apparatus located at a distance from the first. It was, therefore, a practical mechanical problem which Marconi had to meet. Beginning with crude tin boxes set up on poles on the grounds of his father's estate in Italy, he finally devised an apparatus from which a current generated by a battery and passing in brilliant sparks between two brass balls was radiated from a wire suspended on a tall pole. By shutting off and turning on this peculiar current, by means of a device similar to the familiar telegrapher's key, the waves could be so divided as to represent dashes and dots, and spell out letters in the Morse alphabet. This was the transmitter. It was, indeed, simple enough to start these waves travelling through space, to jar the etheric jelly, so to speak; but it was far more difficult to devise an apparatus to receive and register them. For this purpose Marconi adopted a device invented by an Italian, Calzecchi, and improved by a Frenchman, M. Branley, called the coherer, and the very crux of the system, without which there could be no wireless telegraphy. This coherer, which he greatly improved, is merely a little tube of glass as big around as a lead-pencil, and perhaps two inches long. It is plugged at each end with silver, the plugs nearly meeting within the tube. The narrow space between them is filled with finely powdered fragments of nickel and silver, which possess the strange property of being alternately very good and very bad conductors of electrical waves. The waves which come from the transmitter, perhaps 2,000 miles away, are received on a suspended kite-wire, exactly similar to the wire used in the transmitter, but they are so weak that they could not of themselves operate an ordinary telegraph instrument. They do, however, possess strength enough to draw the little particles of silver and nickel in the coherer together in a continuous metal path. In other words, they make these particles "cohere," and the moment they cohere they become a good conductor for electricity, and a current from a battery near at hand rushes through, operates the Morse instrument, and causes it to print a dot or a dash; then a little tapper, actuated by the same current, strikes against the coherer, the particles of metal are jarred apart or "decohered," becoming instantly a poor conductor, and thus stopping the strong current from the home battery. Another wave comes through space, down the suspended kite-wire, into the coherer, there drawing the particles again together, and another dot or dash is printed. All these processes are continued rapidly, until a complete message is ticked out on the tape. Thus Mr. Kemp knew when he heard the tapper strike the coherer that a signal was coming, though he could not hear the click of the receiver itself. And this is in bare outline Mr. Marconi's invention – this is the combination of devices which has made wireless telegraphy possible, the invention on which he has taken out more than 132 patents in every civilised country of the world. Of course his instruments contain much of intricate detail, of marvellously ingenious adaptation to the needs of the work, but these are interesting chiefly to expert technicians.

In his actual transoceanic experiments of December, 1901, Mr. Marconi's transmitting station in England was fitted with twenty masts 210 feet high, each with its suspended wire, though not all of them were used. A current of electricity sufficient to operate some 300 incandescent lamps was used, the resulting spark being so brilliant that one could not have looked at it with the unshaded eye. The wave which was thus generated had a length of about a fifth of a mile, and the rate of vibration was about 800,000 to the second. Following the analogy of the stone cast in the pond with the ripples circling outward, these waves spread from the suspended wires in England in every direction, not only westward toward the cliff where Marconi was flying his kite, but eastward, northward, and southward, so that if some of Mr. Marconi's assistants had been flying kites, say on the shore of Africa, or South America, or in St. Petersburg, they might possibly, with a corresponding receiver, have heard the identical signals at the same instant. In his early experiments Marconi believed that great distances could not be obtained without very high masts and long, suspended wires, the greater the distance the taller the mast, on the theory that the waves were hindered by the curvature of the earth; but his later theory, substantiated by his Newfoundland experiments, is that the waves somehow follow around the earth, conforming to its curve, and the next station he establishes in America will not be set high on a cliff, as at St. John's, but down close to the water on level land. His Newfoundland experiments have also convinced him that one of the secrets of successful long-distance transmission is the use of a more powerful current in his transmitter, and this he will test in his next trials between the continents.

And now we come to the most important part of Mr. Marconi's work, the part least known even to science, and the field of almost illimitable future development. This is the system of "tuning," as the inventor calls it, the construction of a certain receiver so that it will respond only to the message sent by a certain transmitter. When Marconi's discoveries were first announced in 1896, there existed no method of tuning, though the inventor had its necessity clearly in mind. Accordingly the public inquired, "How are you going to keep your messages secret? Supposing a warship wishes to communicate with another of the fleet, what is to prevent the enemy from reading your message? How are private business despatches to be secured against publicity?" Here, indeed, was a problem. Without secrecy no system of wireless telegraphy could ever reach great commercial importance, or compete with the present cable communication. The inventor first tried using a parabolic copper reflector, by means of which he could radiate the electric waves exactly as light – which, it will be borne in mind, is only another kind of etheric wave – is reflected by a mirror. This reflector could be faced in any desired direction, and only a receiver located in that direction would respond to the message. But there were grave objections to the reflector; an enemy might still creep in between the sending and receiving stations, and, moreover, it was found that the curvature of the earth interfered with the transmission of reflected messages, thereby limiting their usefulness to short distances.

In passing, however, it may be interesting to note one extraordinary use for this reflecting system which the inventor now has in mind. This is in connection with lighthouse work. Ships are to be provided with reflecting instruments which in dense fog or storms can be used exactly as a searchlight is now employed on a dark night to discover the location of the lighthouses or lightships. For instance, the lighthouse, say, on some rocky point on the New England coast would continually radiate a warning from its suspended wire. These waves pass as readily through fog and darkness and storm as in daylight. A ship out at sea, hidden in fog, has lost its bearings; the sound of the warning horn, if warning there is, seems to come first from one direction, then from another, as sounds do in a fog, luring the ship to destruction. If now the mariner is provided with a wireless reflector, this instrument can be slowly turned until it receives the lighthouse warning, the captain thus learning his exact location; if in distress, he can even communicate with the lighthouse. Think also what an advantage such an equipment would be to vessels entering a dangerous harbour in thick weather. This is one of the developments of the near future.