Inventors at Work, with Chapters on Discovery

Shaping a Tube.

In another field of ingenuity a great inventor scored a success, simply by deliberately taking a lesson from nature. James Watt, to whom the modern steam engine is most indebted for its excellence, was once consulted by the proprietors of the Glasgow Water Works, as to a difficulty that had occurred in laying pipes across the river Clyde to the Company’s engines: the bed of the river was covered with mud and shifting sand, was full of inequalities, and subject to a current at times of considerable force. With the structure of a lobster’s tail in his mind, Watt drew a plan for an articulated suction-pipe, so jointed as to accommodate itself to the shifting curves of the river-bed. This crustacean tube, two feet in diameter, and one thousand feet in length, succeeded perfectly in its operation. To-day powerful hydraulic dredges discharge through piping with flexible joints such as Watt devised; in one instance this piping is 5700 feet in length.

In many another case art has used a gift of nature simply as received, and then improved upon it. In making their harpoons the Eskimo used the spiral teeth of the narwhal; finding their shape advantageous, they copied it for arrowheads. This is undoubtedly one of the origins of the screw form, of inestimable value to the mechanic and engineer.

Lessons from Lower Animals: A Tool-Using Wasp.

Savages turn birds and beasts to account as food, clothing, and materials for weapons and tools; they also observe with profit the instincts of these creatures. Le Vaillant, the famous explorer, tells us that in Africa the negroes eat any strange food they see the monkeys devour, well assured that it will prove wholesome. When the surveyors of the first transcontinental railroad of America began their labors, they gave diligent heed to the trails of buffaloes in the Rocky Mountains, believing that these sagacious brutes in centuries of quest had discovered the easiest passes. In constructive powers bees, ants and wasps far outrank quadrupeds. Indeed one of the supreme feats of human architecture, the dome, forms part of the nest of the warrior white ant, Termes bellicosus.

It is deemed a mark of unusual intelligence when an ape, of kin to man himself, uses a stone as a hammer wherewith to break open a nut, and yet the like intelligence is displayed by Ammophila urnaria, as described by Dr. and Mrs. George W. Peckham in their charming book, “Wasps Solitary and Social”:[32]

“Just here must be told the story of one little wasp whose individuality stands out in our minds more distinctly than that of any of the others. We remember her as the most fastidious and perfect little worker of the whole season, so nice was she in her adaptation of means to ends, so busy and contented in her labor of love, and so pretty in her pride over the completed work. In filling up her nest she put her head down into it and bit away the loose earth from the sides, letting it fall to the bottom of her burrow, and then, after a quantity had accumulated, jammed it down with her head. Earth was then brought from the outside and pressed in, and then more was bitten from the sides. When at last the filling was level with the ground, she brought a quantity of fine grains of dirt to the spot, and picking up a small pebble in her mandibles, used it as a hammer in pounding them down with rapid strokes, thus making this spot as hard and firm as the surrounding surface.”

It was a wasp, too, which suggested to Reaumur, as he examined its nest, that wood might well serve as the raw material for paper, and serve it does to the amount of millions of tons a year. To-day we have as a new fabric for garments, glanz-stoff, an artificial silk produced from cellulose; its German manufacturers have imitated as nearly as they could the silk-worm’s thread, just as for some years the filaments for incandescent lamps have been made from liquid cellulose forced through minute holes. At first bamboo fibres were used for this purpose; to-day art furnishes a thread of more uniform and lasting quality. This achievement is of a piece with many another. To-day when an inventor seeks to imitate a natural product he does so with a power of analysis, a wealth of new materials, such as his forerunners could not have imagined. It is in laboratories stocked more diversely than ever before, with their resources better understood than at any earlier time, that the triumphs of modern ingenuity proceed.

The Separating Task of the Lungs.

In all likelihood one of the feats of nature soon to be paralleled by art, in an economical way, will be one phase of the breathing process; every time we inflate our lungs their tissues perform a feat which has thus far baffled imitation except in a roundabout and wasteful manner. Air is a mixture of oxygen and nitrogen; the work of life is subserved by the oxygen only, which is separated from air by the lungs and passed into the current of the blood. Oxygen and nitrogen, like any other two gases, tend forcibly to diffuse into each other, as we may see in the distension of a thin rubber sheet dividing a container into two parts, one filled with oxygen, the other with nitrogen. To overcome the force of diffusion which keeps together the oxygen and nitrogen forming a cubic foot of air, of ordinary temperature, would require such an effort as would lift twenty-one pounds one foot from the ground. This task the lungs accomplish by means which elude observation or analysis. It would mean much to the arts if this parting power could be imitated simply and cheaply. In common combustion each volume of oxygen which unites with the fuel, carries with it four volumes of nitrogen which have to be heated, not only reducing the temperature of the flame, but removing in sheer waste much of the heat. A supply of oxygen free from admixture would double the value of fuel for many purposes, creating a temperature so high that it would be difficult to find building materials refractory enough for the furnaces. Cheap oxygen would greatly increase the light derivable from oil and gas, as proved in the brilliancy of an oxyhydrogen jet. In bleaching and in scores of other processes, oxygen is so valuable that, notwithstanding its present cost, the demand for it steadily increases. Cannot the lungs, chemically or mechanically, be copied so as to yield this gas at a low price for a thousand new services?

In addition to separating oxygen from air our vital organs are every moment performing chemical tasks just as elusive. The liver, for instance, is a sugar-maker. The elaboration of living tissue is of transcendent interest to the physiologist; it is fraught with the same attraction to the chemist who would build compounds from their elements, to the engineer who would transform heat or chemical energy into motive power with less than the enormous loss of our present methods.

Flight.

In 1887 the late Professor S. P. Langley of Washington began experiments in mechanical flight. He found that one horse-power will support in calm air and propel at forty-five miles an hour a wing-plane weighing 209 pounds. Dr. A. F. Zahm, of the Catholic University of America, at Washington, has recently ascertained that a thin foot-square gliding plane weighing one pound soars with the least expenditure of power at about 40 miles an hour, while at 80 miles the power required is more than twice as much. As engines have been made weighing less than ten pounds per horse-power, capable of yielding a horse-power for five hours with four pounds of oil, we are plainly approaching the mastery of the air,—so freely exercised by the sparrow and the midge. Among the students eager in this advance are the men who examine with the camera how wings of diverse types behave in flight, and then endeavor to imitate the strongest and swiftest of these wings.

Light.

Professor Langley conducted another inquiry of fascinating interest, this time respecting those natural light-producers, the fireflies, especially the large and brilliant species indigenous to Cuba, Pyrophorus noctilucus. As the result of refined measurements with the spectroscope and the bolometer, the most delicate heat detector known to the laboratory, he said: “The insect spectrum is lacking in rays of red luminosity and presumably in the infra-red rays, usually of relatively great heat, so that it seems probable that we have here light without heat.” When we remember that ordinary artificial light is usually accompanied by fifty to a hundred times as much energy in the form of wasteful and injurious heat, we see the importance of this research. If light can be produced without heat by nature, why not also by art?

Converting Heat Into Work.

Another notable case of efficiency in nature has already been remarked, namely, the conversion by the animal frame of fuel-values into mechanical work. This is of a piece with the chief task of the engineer as he puts his engines in motion by burning coal or wood, oil or gas. It is a remarkably good steam engine which yields as much as one tenth as a working dividend. Gas engines have sprung into wide popularity because they yield larger results, in extremely favorable cases reaching thirty per cent. A heat engine, of any type, has its effectiveness measured by comparing in absolute units the heat which enters it with the heat which remains after its work is done. The zero of the absolute scale is 460° below the zero of Fahrenheit. So that if an engine begins work at 920° Fahr. (1380° absolute), and the working substance is lowered in temperature by its action in the machine until it falls to 460° Fahrenheit (920° absolute), the engine has a gross efficiency of one third. Economy depends upon employing a working substance at the highest feasible temperature in such a mode that it leaves the engine at the lowest temperature possible. Hence we see engineers devising superheaters for their steam, and producing metal surfaces which either need no lubrication at all, or employ such a lubricant as graphite, which bears high temperatures without injury.

Now let us glance at the mechanism of our own frames, which, according to Professor W. O. Atwater, converts about twenty per cent. of the energy value of our food into mechanical work. This is a remarkable performance, especially when we remember that in health the bodily warmth does not rise above 98° Fahrenheit. What explains this amazing effectiveness at a temperature so far below that of either a steam engine or a gas engine? A simple experiment may be illuminating. We take a plate of zinc and a plate of copper; although they seem to be at rest we know them to be in active molecular motion, which motion is set free when they combine with oxygen or other elements. This combination may take place in two quite different ways, which we will now compare. In a glass jar, nearly filled with a solution of sulphuric acid and water, we immerse the plates of zinc and copper without their touching each other; both rise in temperature as they corrode, as they unite with oxygen from the surrounding liquid. We may, if we wish, employ this heat in driving an air engine; but we can do better than that, for an air engine wastes most of the heat supplied to it. We stop the heating process by joining the two plates with a wire through which now passes an electric current, our simple apparatus now forming a common voltaic cell. This current we apply to lift weights, propel a fan, or execute any other task we please, all with scarcely any waste of energy whatever. The instructive point is that now chemical union is taking place without heat, in a mode vastly more economical and easy to manage than if we allowed heat to be generated, and then applied it in an engine to perform work. The conclusion is irresistible: in the animal frame the conversion of molecular energy into muscular motion is by electrical means and no other. When the engineer learns in detail how the task is executed, and imitates it with success; he will escape the tax now imposed on every engine which sets its fuel on fire as the first step in converting latent into actual motion.

Foresight Instead of Hindsight.

While inventors in the past might have taken many a hint from nature, as a matter of fact they seldom did so, but went ahead, hit-or-miss, failing to observe that what they reached with much laborious fumbling, often they might have copied directly from nature. In Colorado and California we admire the dams which are convex upstream, withstanding in all the strength of an arch a tremendous pressure: this very plan is adopted by beavers when they build in a swift current, as one may see in many streams of the Adirondacks. In the rearing of irrigation dams, in tasks much more difficult, human progress has gone forward by empirical attempts one after another, and science has followed, long afterward, to give reasons for any success arrived at by rule-of-thumb. But this blundering hindsight is being replaced by a foresight which first spies out what may be hit, and then never wastes an arrow. Professor R. H. Thurston has said:—“Bleaching and dyeing flourished before chemistry had a name; the inventor of gunpowder lived before Lavoisier; the mariner’s compass pointed the seaman to the pole before magnetism took form as a science. The steam engine was invented and set at work, substantially as we know it to-day, before the science of thermodynamics was dreamt of; the telegraph and the telephone, the electric light and the railroad have made us familiar with marvels greater than those of fiction, and yet they have been principally developed, in every instance, by men who had acquired less of scientific knowledge than we demand to-day of every college-bred lad.”

To-day the leaders in applied science are of quite other stamp. They keenly observe what nature does, either in spontaneous chemical activities or in the functions of a plant or an animal, then analyzing the process with more and more insight and accuracy, they ask, How may this with economy and profit be imitated by art? A feat of Professor Henri Moissan is typical in this regard. In studying diamonds he became convinced that they have been produced in nature from ordinary carbon subjected to extreme temperatures and pressures. Imitating these heats and pressures as well as he could, he manufactured diamonds from common graphite in an electrical furnace. These gems are small, but they gleam with promise of what the fully armed physicist and chemist may achieve in duplicating the gifts of nature in the light of new knowledge, by dint of new resources.

CHAPTER XIX
ORIGINAL RESEARCH

Knowledge as sought by disinterested inquirers . . . A plenteous harvest with but few reapers . . . Germany leads in original research . . . The Carnegie Institution at Washington.

We have now taken a rapid survey of invention and discovery in the fields of Form, Size, Properties, Measurement, and the Teachings of Nature. We will here somewhat change our point of view and bestow a glance at the characteristics of inventors and discoverers, noting their powers of observation and experiment, their patience from first to last in learning from other thinkers and workers past and present. What any one man, however able, can discover or invent, is the merest trifle in comparison with the resources accumulated since the dawn of human wit. And yet in adding a little to what he has learned, that little welds and vivifies his education as nothing else can. In setting out to add to known truth there must be a goodly equipment in knowledge and skill. Knowledge, therefore, may serve as a starting point for the survey before us.

Knowledge Necessary.

Success in discovery and invention, as in the case of a Newton or a Watt, depends not only upon rare natural faculty, but upon knowledge. Dr. Pye-Smith, of London, an eminent physician, says:—“Some would have us believe that erudition is a clog upon genius. This question has often been discussed, and it has even been maintained that he is most likely to search out the secrets of nature who comes fresh to the task with faculties unexhausted by prolonged reading, and his judgment uninfluenced by the discoveries of others. This, however, is surely a delusion. Harvey could not have discovered the circulation of the blood had he not been taught all that had been previously learned of anatomy. True, no progress can be made by the mere assimilation of previous knowledge. There must be an intelligent curiosity, an observant eye, and intellectual insight. Few things are more deplorable than to see talent and industry employed in fruitless researches, partly rediscovering what is already fully known, or stubbornly toiling along a road which has long ago been found to lead no whither. We must then instruct our students to the utmost of our power. Whether they will add to knowledge we cannot tell, but at least they shall not hinder its growth by their ignorance. The strong intellect will absorb and digest all that we put before it, and will be all the better fitted for independent research. The less powerful will at least be kept from false discoveries and will form, what genius itself requires, a competent and appreciative audience.”

American inventors echo the dictum of the English physician. Says Mr. Octave Chanute:—“It has taken many men to bring any great invention to perfection, the last successful man adding little to what was previously known. As a rule the basis of his success lies in a thorough acquaintance with what has been done before him, and his setting about his work in a thoroughly scientific way.” Professor W. A. Anthony observes:—“If the army of would-be inventors would enter the field with a full knowledge of what science has already done, the conquest of new territory would be rapidly accomplished.” To the same effect speaks Mr. Leicester Allen:—“While rarely there appears a man so highly endowed by nature with originating faculty that we call his talent genius, it will be found in the last analysis that his inventive power lies, not in some vague, mysterious intuition, but in a logical mind that can draw correct inferences from established premises; in an analytical mind that enables him to reason from correct data, discovering those which are false; in natural and cultivated perceptive faculties that enable him to determine the effect of a given set of conditions, and through exercise of which he is able to place clearly before his mental vision the exact statement or proposition which defines the thing to be accomplished; in the ability to concentrate his attention upon the problem in hand to the exclusion of everything else, for the time being, and a perseverance that will not be denied—that failure cannot wear out.”

Much is Still to be Discovered.

“To many,” says Sir Michael Foster, Professor of Physiology at Cambridge, “scientific knowledge seems to be advancing by leaps and bounds; every day brings its fresh discovery, opening up strange views, turning old ideas upside down. Yet every thoughtful man of science who has looked round on what others beside himself are doing will tell you that nothing weighs more heavily on his mind than this: the multitude of questions crying aloud to be answered, the fewness of those who have at once the ability, the means, and the opportunity of attempting to find the answers. Among the many wants of a needy age, few, if any, seem to him more pressing than that of the adequate encouragement and support of scientific research.” With his own field of science in view he continues: “We want to know more about the causation and spread of disease and about the circumstances affecting health before we can legislate with certainty of success. At home we want to know more about the spread of tubercle, of typhoid fever, and other infectious diseases; we want to know more about the proper means to secure that the water we drink, the food we eat, and the air we breathe, should not be channels of disease; we want to know more about the invisible elfic micro-organisms which swarm around us, to learn which are our friends, and which our foes, how to nourish the one, how to defeat the other; we want to know the best way to shield man in the factory and the workshop against the works of man.”

As to the fewness of those who have the highest capacity for original research, who have it in them to add to known truth in a notable way, Professor Simon Newcomb of Washington, the acknowledged dean of science in America, has said:—“It is impressive to think how few men we should have to remove from the earth during the past three centuries to have stopped the advance of our civilization. In the seventeenth century there would only have been Galileo, Newton and a few other contemporaries; in the eighteenth, they could almost have been counted on the fingers; and they have not crowded the nineteenth. Even to-day, almost every great institution for scientific research owes its being to some one man, who, as its founder or regenerator, breathed into it the breath of life. If we think of the human personality as comprehending not merely mind and body, but all that the brain has set in motion, then may the Greenwich Observatory of to-day be called Airy; that of Pulkowa, Struve; the German Reichsanstalt, Helmholtz; the Smithsonian Institution, Henry; the Harvard Museum of Comparative Zoölogy, Agassiz; the Harvard Observatory, Pickering.”

Planning an Inquiry.

The late Professor Robert H. Thurston, of Cornell University, once said:—“Methods of planning scientific investigation involve, first, the precise definition of the problem to be solved; secondly, they include the ascertainment of ‘the state of the art,’ as the engineer would say, the revision of earlier work in the same and related fields, and the endeavor to bring all available knowledge into relation with the particular case in hand; then the investigator seeks information which will permit him, if possible, to frame some theory or hypothesis regarding the system into which he proposes to carry his experiment, his studies, and his logical work, such as will serve him as a guide in directing his work most effectively.

“The empirical, the imaginative, and even the guess work systems, or perhaps lack of system, have their place in scientific research. The dim Titanic figure of Copernicus seems to rear itself out of the dull flats around it, pierces with its head the mists that overshadow them and catches the first glimpse of the rising sun. But first Copernicus made a shrewd guess, and then followed with mathematical work and confirmation. . . . Kepler, also, was strong almost beyond competition in speculative subtlety and innate mathematical perception. . . . For nineteen years he guessed at the solution of a well-defined problem, finding his speculation wrong every time, until at last a final trial of a last hypothesis gave rise to deductions confirmed by observation. His first guess was that the orbits of the planets were circular, next that they were oval, and last that they were elliptical.”

Pascal, great in what he knew, was great also in what he was. Walter Pater thus depicts his powers:—“Hidden under the apparent exactions of his favorite studies, imagination, even in them, played a large part. Physics, mathematics, were with him largely matters of intuition, anticipation, precocious discovery, short cuts, superb guessing. It was the inventive element in his work, and his way of painting things that surprised those most able to judge. He might have discovered the mathematical sciences for himself, it is alleged, had his father, as he once had a mind to do, withheld him from instruction in them.”

No such gift of intuition as that displayed by Pascal fell to the lot of Buffon, who tells us:—“Invention depends on patience. Contemplate your subject long. It will gradually unfold itself, till an electric spark convulses the brain for a moment.”

As to the modes in which invention manifests itself, Mr. William H. Smyth says:—“Examine at random any one of half a dozen lines of mechanical invention, one characteristic common to them all will instantly arrest attention—they present nothing more than a mere outgrowth of the manual processes and machines of earlier times. Some operation, once performed by hand tools, is expedited by a device which enables the foot as well as the hand to be employed. Then power is applied; the hand or foot operation, or both, are made automatic, and possibly, as a still further improvement, several of these automatic devices are combined into one. All the while the fundamental basis is the old, original hand process; hence, except in the extremely improbable event that this was the best possible method, all the successive improvements are simply in the direction, not of real novelty, but of mere modification and multiplication. The most important and radical departures from old methods, by which many of the industries of the world have been completely revolutionized, are nearly always originated by persons wholly ignorant of the accepted practice in the particular industry concerned. The first and most important prerequisite to invention is an absolutely clear insight into, and a comprehensive grasp of, all the conditions involved in the problem. A scheme for the cultivation of invention should in part include:—(1) Accurate and methodical observation. (2) Cultivation of memory and the faculty of association. (3) Cultivation of clear visualization. (4) Logical reasoning from actual observation. The course should include exercises in drawing from simple objects, and the solution of a simple problem, such as that of a can-soldering machine.”

The Debt to Research in Medicine.

Investigators are never so useful as when thoroughly disinterested; let them find what they may, it will either have worth in itself or lead to something which has. Dr. Pye-Smith says:—

“Facts have been found at every step of science which were valueless at their discovery, but which, little by little, fell into line and led to applications of the highest importance—the observation of the tarnishing of silver, the twitching of the frog’s leg, were the origin of photography and telegraphy; the abstract problem of spontaneous generation gave rise to the antiseptics of surgery. . . . In medicine, as in every other practical art, progress depends upon knowledge, and knowledge must be pursued for its own sake without continually looking about for its practical applications. Harvey’s great discovery of the circulation of the blood was a strictly physiological discovery, and had little influence upon the healing art until the invention of auscultation. So, also, Dubois Reymond’s investigation of the electrical properties of muscle and nerve was purely scientific, but we use the results thus obtained every day in the diagnosis of disease, in its successful treatment, and in the scarcely less important demonstration of the falsehoods by which the name of electricity is used for purposes of gain. The experiments on blood pressure, begun by Hales, and carried to a successful issue in our own time by Ludwig, have already led to knowledge which we use every day by the bedside, and which only needs the discovery of a better method of measuring blood pressure during life to become one of our foremost and most practical aids in treatment. Again, we can most of us remember using very imperfect physiological knowledge to fix, more or less successfully, the locality of an organic lesion of the brain. I also remember such attempts being described as a mere scientific game, which could only be won after the player was beaten, since when the accuracy of diagnosis was established, its object was already lost; but who would say this now, when purely physiological research and purely diagnostic success have led to one of the most brilliant achievements of practical medicine, the operative treatment of organic diseases of the brain?”

The prevention of disease, as important as its cure, owes an incalculable debt to Louis Pasteur. De Varigny says in “Experimental Evolution”:—

“Pasteur, about 1850, spent a long time in seemingly very speculative and very idle studies of dissymmetry and symmetry in various crystals, especially those of tartaric acid; the practical value of such investigations seemed to be naught, and at all events it had no interest save for the elucidation of some points in crystallography. But this investigation led logically to the study of fermentation, and the final outcome of Pasteur’s work has been—leaving out the stepping stones—the discovery of the real cause of a large number of diseases, the cure of one of them, and the expectation, based on facts, that all these diseases can be defeated by appropriate methods.”

What is true in medicine is equally true in physics. Concerning the debt of the inventor to the man of physical research, Mr. Addison Browne has this to say:—

Research in Physics and Chemistry.

“A few weeks ago I was talking with an electrician who has made several very interesting and important inventions. I asked him of how much importance he conceived that the scientific men of the closet, the original investigators, so-called, had been in working out the great inventions of electricity during the last fifty years—telegraphs, cables, telephones, electric lighting, electric motors; and whether these achievements were not in reality due mainly to practical men, the inventors who knew what they were after, rather than to the men of science who rarely applied their work to practical use. He said, ‘The scientific men are of the utmost importance; everything that has been done has proceeded upon the basis of what they have previously discovered, and upon the principles and laws which they have laid down. Nowadays we never work at random—I go to my laboratory, study the application of the principles, facts and laws which the great scientists like Faraday, Thomson and Maxwell have worked out, and endeavor to find such devices as shall secure my aim.’ As Tyndall said, ‘Behind all our practical applications there is a region of intellectual action to which practical men have rarely contributed, but from which they draw all their supplies. Cut them off from that region and they become eventually helpless.’”

Research is golden only when brought to fruit by co-operation. To quote Professor Tyndall:—

“To keep science in healthy play three classes of workers are necessary: (1) The investigators of natural truth, whose vocation it is to pursue that truth, and extent the field of discovery for its own sake, without reference to practical ends. (2) The teachers who diffuse this knowledge. (3) The appliers of these principles and truths to make them available to the needs, the comforts, or the luxuries, of life. These three classes ought to co-exist and interact.”

Concerning the larger problems of engineering research, Professor Osborne Reynolds, of Owens College, Manchester, says:—

“Every one who has paid attention to the history of mechanical progress must have been impressed by the smallness in number of recorded attempts to decide the broader questions in engineering by systematic experiments, as well as by the great results which, in the long run, have apparently followed as the effect of these few researches. I say ‘apparently,’ because it is certain that there have been other researches which probably, on account of failure to attain some immediate object, have not been recorded, although they may have yielded valuable experience which, though not put on record, has, before it was forgotten, led to other attempts. But even discounting such lost researches it is very evident that mechanical science was in the past very much hampered by the want of sufficient inducement to the undertaking of experiments to settle questions of the utmost importance to scientific advance, but which have not promised pecuniary results, scientific questions which involved a greater sacrifice of time and money than the individuals could afford. The mechanical engineers recently induced Mr. Beauchamp Towers to carry out his celebrated researches on the friction of lubricated journals, the results of which research certainly claim notice as one of the most important steps in mechanical science.”

Lord Rayleigh has said:—

“The present development of electricity on a large scale depends as much upon the incandescent lamp as the dynamo. The success of these lamps demands a very perfect vacuum—not more than one millionth of the normal quantity of air should remain. It is interesting to recall that in 1865 such vacua were rare even in the laboratory of the physicist. It is pretty safe to say that these wonderful results would never have been accomplished had practical applications alone been in view. The way was prepared by an army of men whose main object was the advancement of knowledge, and who could scarcely have imagined that the processes which they had elaborated would soon be in use on a commercial scale and entrusted to the hands of ordinary workmen.” He adds:—“The requirements of practice react in the most healthy manner upon scientific electricity. Just as in former days the science received a stimulus from the application to telegraphy, under which everything relating to measurement on a small scale acquired an importance and development for which we might otherwise have had long to wait, so now the requirements of electric lighting are giving rise to a new development of the art of measurement on a large scale, which cannot fail to prove of scientific as well as practical importance.”

Regarding the territory likely to yield most fruit to the researcher, he observes:—“The neglected border land between two branches of knowledge is often that which best repays cultivation; or, to use a metaphor of Maxwell’s, the greatest benefits may be derived from a cross-fertilization of the sciences.”

The Example of Germany.

Why Germany leads the world in science becomes clear when we observe her co-ordination of industry with the higher education and with original research. Professor Wilhelm Ostwald has said:—“When the student in Germany has finished his university course he is still entirely free to choose between a scientific and a technical career. . . . The occupation of a technical chemist in works is very often almost as scientific in its character as in a university laboratory. . . . The organization of the power of invention in manufactures on a large scale in Germany is, as far as I know, unique in the world’s history, and is the very marrow of our splendid triumphs. Each large works has the greater part of its scientific staff—and there are often more than a hundred doctors of philosophy in a single manufactory—occupied not in the management of the manufacture, but in making inventions. The research laboratory in such works is only different from one in a university from its being more splendidly and sumptuously fitted. I have heard from the business managers of such works that they have not infrequently men who have worked for four years without practical success; but if they have known them to possess ability they keep them notwithstanding, and in most cases with ultimate success sufficient to pay all expenses.”

Mr. Carnegie’s Aid to Original Research.

In 1902 Mr. Andrew Carnegie, with a gift of ten million dollars, founded in Washington the Carnegie Institution for Original Research. Its president is Dr. R. S. Woodward, formerly of Columbia University, New York. One of its first enterprises was to establish at Cold Spring Harbor, New York, a station for experimental evolution directed by Dr. Charles B. Davenport. Here will be extended the remarkable experiments of Dr. Hugo de Vries, of Amsterdam, who discovered that the large-flowered evening primrose suddenly gives rise to new species. Other experiments are in progress with regard to the variability of insects, the hybridization of plants and animals. A marine biological laboratory has been established at Tortugas, Florida; and a desert botanical laboratory at Tucson, Arizona. In its grants for widely varied purposes the policy of the Institution is clear: only those inquiries are aided which give promise of fruit, and in every case the grantee requires to be a man of proved ability, care being taken not to duplicate work already in hand elsewhere, or to essay tasks of an industrial character. Experience has already shown it better to confine research to a few large projects rather than to aid many minor investigations with grants comparatively small.

One branch of the work reminds us of Mr. Carnegie’s method in establishing public libraries—the supplementing of local public spirit by a generous gift. In many cases a university or an observatory launches an inquiry which soon broadens out beyond the range of its own small funds; then it is that aid from the Carnegie Institution brings to port a ship that otherwise might remain at sea indefinitely. Let a few typical examples of this kind be mentioned:—Dudley Observatory, Albany, New York, and Lick Observatory, California, have received aid toward their observations and computations; Yerkes Observatory, Wisconsin, has been helped in measuring the distances of the fixed stars. Among other investigations promoted have been the study of the rare earths and the heat-treatment of some high-carbon steels. The adjacent field of engineering has not been neglected: funds have been granted for experiments on ship resistance and propulsion, for determining the value of high pressure steam in locomotive service. In geology an investigation of fundamental principles has been furthered, as also the specific problem of the flow of rocks under severe pressure. In his remarkable inquiry into the economy of foods, Professor W. O. Atwater, of Wesleyan University, Middletown, Connecticut, has had liberal help. In the allied science of preventive medicine a grant is advancing the study of snake venoms and defeating inoculations.

At a later day the Institution may possibly adopt plans recommended by eminent advisers of the rank of Professor Simon Newcomb, who points out that analysis and generalization are to-day much more needed than further observations of a routine kind. He has also had a weighty word to say regarding the desirability of bringing together for mutual attrition and discussion men in contiguous fields of work, who take the bearings of a great problem from different points of view.

Speaking of the study of human life and society, Professor Karl Pearson is clear that both thorough training as well as sound theories are needed if research is to be fruitful. In the course of a letter to the Carnegie Institution, he says:—“Biological and sociological observations in too many cases are of the lowest grade of value. Even where the observers have begun to realize that exact science is creeping into the biological and sociological fields they have not understood that a thorough training in the new methods is an essential preliminary for effective work, even for the collection of material. They have rushed to measure or count every living form they could hit on, without having planned at the start the conceptions and ideas that their observations were intended to illustrate. I doubt whether even a small proportion of the biometric data being accumulated in Europe and America could by any amount of ingenuity be made to provide valuable results, and the man capable of making it yield them would be better employed in collecting and reducing his own material.”

Professor Edward C. Pickering, Director of the Harvard Observatory, has suggested that astronomers the world over resolve themselves into a committee of the whole for the attack of great questions, the work to be duly parcelled out among the observatories best placed and equipped for specific tasks, to the end that repetition be avoided and a single, comprehensive plan be pursued. Not only in astronomy but in every field of science such concerted attack would have great value. In engineering, for example, there are questions as to the durability of steels and other building materials, which when investigated would yield rich harvests to every practicing engineer on the globe. It may be expected that in effecting co-ordinations of this kind the Carnegie Institution will play a notable part in the science of the twentieth century.

CHAPTER XX
OBSERVATION

What to look for . . . We may not see what we do not expect to see . . . Lenses reveal worlds great and small otherwise unseen . . . Observers of the heavens and of seashore life . . . Collections aid discovery . . . Happy accidents turned to profit . . . Value of a fresh eye . . . Popular beliefs may be based on truth . . . An engineer taught by a bank swallow.

Ability to observe is an unfailing mark of an inventor or discoverer: it is quite as much a matter of the mind as of the eye. A botanist, keenly alive to varieties of hue, of form in leaves, tendrils, and petals may not give a second glance to stratifications which rivet the gaze of a geologist for hours together. Each sees what he knows about, what he is interested in, what he brings the power and desire to see. When Faraday was asked to witness an experiment he always said: “What is it that I am to look for?” He knew the importance of concentrating his attention on the very bull’s eye of a target.

How much goes to sound observing is thus stated by John Stuart Mill,—“The observer is not he who merely sees the thing which is before his eyes, but he who sees what parts the thing is composed of. One person, from inattention, or attending only in the wrong place, overlooks half of what he sees; another sets down much more than he sees, confounding it with what he imagines, or with what he infers; another takes note of the kind of all the circumstances, but being inexpert in estimating their degree, leaves the quantity of each vague and uncertain; another sees indeed the whole, but makes such an awkward division of it into parts, throwing into one mass things which require to be separated, and separating others which might more conveniently be considered as one, that the result is much the same, sometimes even worse than if no analysis had been attempted at all.”

How an explorer of ability may witness a new fact without realizing that it points to a great industry, is shown in the case of Lord Dundonald. In 1782, or thereabout, near Culross Abbey in Scotland, he built a tar-kiln. Noticing the inflammable nature of a vapor arising during the distillation of tar, the Earl, by way of experiment, fitted a gun-barrel to the eduction pipe leading from the condenser. On applying fire to the muzzle, a vivid light blazed forth across the waters of the Frith, distinctly visible on the opposite shore. Soon afterward the inventor visited James Watt at Handsworth, near Birmingham, and told him about the gas-lighting at the kiln, but his host paid no attention to the matter. His assistant, William Murdock, however, was impressed by the story, and some years later applied gas to the illumination of the Soho works where Watt’s engines were built. This was the beginning of gas-lighting as a practical business.

Professor Adam Sedgwick, of Cambridge University, famous as a geologist, and Charles Darwin once took an excursion in Wales amid markings of extraordinary interest which neither of them noticed. Darwin tells us: “I had a striking instance of how easy it is to overlook phenomena, however conspicuous, before they have been observed by any one. We spent many hours at Cwm Idwal, examining the rocks with extreme care, as Sedgwick was anxious to find fossils in them, but neither of us saw a trace of the wonderful glacial phenomena all around us; we did not notice the plainly scored rocks, the perched boulders, the lateral and terminal moraines, yet these phenomena are so conspicuous that, as I declared in a paper published many years afterward, a house burnt down by fire could not tell its story more plainly than did this valley. If it had been filled with a glacier, the phenomena would have been less distinct than they now are.” At a later day when Darwin’s powers of observation had become acute in the highest degree, he noticed a bird’s feet covered with dirt. Rather a common fact, not worth dwelling on, earlier observers had supposed. Not so thought Darwin. He carefully washed the bird’s feet, and planting the removed solids he was rewarded with several strange plants brought from afar by his winged visitor.

A cousin to Charles Darwin, Francis Galton, is an investigator of eminence. In a study of visual memory, a faculty in which observation bears its best fruits, he says:—

“It is a mistake to suppose that sharp sight is accompanied by clear visual memory. I have not a few instances in which the independence of the two faculties is emphatically commented upon; and I have at least one clear case where great interest in outlines and accurate apprehension of straightness, squareness, and the like, is unaccompanied by the power of visualizing.”

A new instrument, machine or engine is imagined by its creator long before it takes actual form; everything he sees that will be of help he builds at once into his design, everything else, however interesting in itself, he passes with a heedless eye.

Think Birds and You Shall See Birds.

“If we think birds, we shall see birds wherever we go,” says John Burroughs. An observer faithful and accurate in noticing birds and beasts, rocks and leaves, may come at last upon a flower which opens a sphere of knowledge wholly new, as when the round-leaved sun-dew was first observed to entrap and feed upon insects. Much, also, depends upon comparisons such as occur only to a mind at once broad and alert. One may notice in spring and early summer a few leaves growing directly from the trunk of a tree, sometimes near the ground. In maples these leaves are decidedly narrower than those growing from branches in the usual way, and they often have a reddish tinge. Comparing a variety of such leaves with fossil impressions of allied species, Professor Robert T. Jackson of Boston came upon an interesting discovery. He found that these sporadic leaves closely resemble those borne by the remote ancestors of our present trees: they are the lingering reminders of a far distant day.

An observation equally keen saved the orange groves of California from destruction by the fluted scale insect. In 1890, or thereabout, the orange growers in their extremity sought the advice of Professor C. V. Riley, entomologist to the Department of Agriculture at Washington. He asked: “Where did the pest come from?” “Australia,” was the answer. “Is it much of a nuisance there?” “Not particularly.” “Then what keeps it down, what preys upon it?” “Nothing specially,” was the response. Dissatisfied with this answer, Professor Riley sent to Australia a trained entomologist and acute observer, Mr. Albert Koebele, who gathered various insects noticed as preying upon the fluted scale. Distributing these upon his arrival in California he was fortunate enough to find that one of his assisted emigrants, a lady bird, Vedalia cardinalis, fed so ravenously upon the fluted scale as to restrict its ravages to quite moderate proportions.

It was an equally disciplined eye which in the laboratory first noticed that air is non-conducting until traversed by an X-ray, when it becomes conducting in a noteworthy degree. The field of radio-activity, at which we have glanced in this book, owes its cultivation to observers keen to note phenomena utterly unlike those before dwelt upon by the human eye. Often close observers learn what would never be imagined as possible: in rifle-making the tendency of the drills, which revolve nearly a thousand times a minute, to follow the axial line in a revolving bar is a fact which may be accounted for after observation, but which no one would predict.

One day on the Glasgow and Ardrossan Canal a spirited horse took fright; it was then observed, with astonishment, that a boat, the “Raith,” to which it was attached, for all its increased speed, went through the water with less resistance than before. The vessel rode on the summit of a wave of its own creation with this extraordinary effect. The “Raith,” said Mr. Scott Russell, “weighed 10,239 pounds, requiring a force of 112 pounds to drag it at 4.72 miles an hour; 275 pounds at 6.19 miles an hour, and but 268¹⁄₂ pounds at 10.48 miles per hour.” Thus paradoxically was reversed the rule that the resistance of a vessel increases rapidly as she is moved through the water. Mr. Russell added:—“Some time since a large canal in England was closed against general trade by want of water, drought having reduced the depth from 12 to 5 feet. It was then found that the motion of the light boats was more easy than before; the cause was obvious. The velocity of the wave was so much reduced by the diminished depth, that, instead of remaining behind the wave, the vessels rode on its summit.”

The Mississippi Jetties of James B. Eads.

One of the most difficult problems ever solved by an American engineer was the making navigation safe for vessels of fairly deep draft in the lower branches of the Mississippi. The difficulties were overcome by James B. Eads, of St. Louis, in his system of jetties. He remarked, says his biographer, Mr. Louis How, that other things being equal, the amount of sediment which a river can carry is in direct proportion to its velocity. When, for any reason, the current becomes slower at any special place, it drops part of its burden of sediment at that place, and when it becomes faster again it picks up more. Now, one thing that makes a river slower is an increase of its width, because then there is more frictional surface; and contrariwise, one of the things that makes it faster is a decrease of its width. Narrow the Mississippi then, at its mouth, said Eads, and it will become swifter there, and consequently will remove its soft bottom by picking up the sediment (of which it will then hold much more), and by carrying it out to the gulf, to be lost in deep water and swept away by currents, you will have your deep channel. In other words, if you give the river some assistance by keeping its current together, it will do all the necessary labor and scour out its own bottom. This sound reasoning, based upon observation as sound, was duly embodied in a series of jetties which have proved successful.

Observation Suggests an Experiment.

Such a river as the Mississippi taking its source through an alluvial plain, has bends which go on increasing by the wearing away of the outer banks, and the deposition of mud, sand and gravel on the inner bank. In 1876 at the Glasgow meeting of the British Association for the Advancement of Science, Professor James Thomson showed a model which made the phenomena of the case perfectly clear. A stream eight inches wide and less than two inches deep, flowed round a bend. As it turned this bend the water exerted centrifugal force, while a thin layer of the water at the bottom, representing a similar layer close to a river-bed, was retarded by its friction with the remainder of the stream, exerting less centrifugal force than like portions of the larger body of water flowing over it farther away from the bottom. Consequently the bottom layer flowed in obliquely across the channel toward the inner bank; rising up in its retarded motion betwixt the fast flowing water it protected the inner bank from scour. At the same time this retarded current brought with it sand and other detritus from the bottom, duly deposited along the inner bank of the stream.

Instrumental Aids to Observation.

The powers of the eye, acute as they are, have narrow limits; inestimable therefore is the value of the microscope, the telescope and the camera which bring to view uncounted images otherwise unseen. Let us remark how in the early days of instrumental aids a great observer just missed noting a phenomenon of utmost importance,—the black lines of the solar spectrum, upon which Fraunhofer, an optician of Munich, based his spectroscope. In sending a solar beam through a lens and a prism Sir Isaac Newton admitted the rays through an oblong slit at times as narrow as one twentieth of an inch. He saw the familiar colors, from red to violet, and nothing more. Even with a crown lens, such as he probably used, four lines distinctly appear; that is, they appear to-day, to an observer who is looking for them. In 1802 these lines were observed, as far as we know, for the first time on record, by Dr. Wollaston, who drew six of them in a diagram accompanying a paper in the Philosophical Transactions. Four of these lines he regarded as boundaries of the colors of the spectrum; of the other two lines he attempted no explanation. He used prisms of various materials but found no alteration in the lines while he studied a sunbeam. When he employed candles or an electric light he found the appearances different, why, he could not undertake to explain. In 1814, Fraunhofer observed these lines in detail, mapped them, and proved that they identified elements long known to chemists. As he built his spectroscope he gave the chemist, the physicist and the astronomer an instrument of research worthy a place beside either the microscope or the telescope.

Dr. Wollaston, in 1802, as we have seen stood upon the threshold of spectroscopy without knowing it. During the same year he performed an experiment which took him into the field of photography without his recognizing the possibilities of that wonderful art. He took paper which had been dipped in muriate of silver and caught on its surface impressions of the ultra-violet light in a solar spectrum. These rays, as rings, were reflected from a thin plate of air, as in the case of the colors of thin plates, at distances corresponding to their proper places in the spectrum. Thus was established the close analogy between rays visible and invisible, and by a method destined to give mankind a universal limner in light of all kinds, and in much radiance which is not luminous at all.

Two Observers of the Skies.

Edward Emerson Barnard, of the Yerkes Observatory, Williams Bay, Wisconsin, is in the first rank of living astronomers. Among his many discoveries the most remarkable is that of the fifth satellite of Jupiter at the Lick Observatory. His early work at the Vanderbilt Observatory, Nashville, gave full promise of his later achievements. One evening in November, 1883, he was observing an occultation of the well-known star Beta Capricorni by the moon. He had patiently waited for his opportunity; such an occultation is best seen when the moon is a small crescent, the star disappearing at the dark curve of the moon where its beams do not overpower the feeble stellar ray. When the moon passes between the eye and a fixed star, the disappearance of the star is instantaneous. At the distance from which we look at it the star is a point only, and as the moon has no atmosphere, the instant the edge of the lunar surface touches the line joining the eye of the observer with the star, it vanishes from sight. When the moon passed in front of Beta Capricorni Mr. Barnard noticed that instead of disappearing at once, there was a sudden partial diminution of the light of the star, then a total extinction of the remaining point. The interval between the diminution and complete extinction of the light occupied only a few tenths of a second, but it was long enough to put his keen mind upon inquiry. Mr. Barnard in an astronomical journal called attention to the phenomenon and suggested that instead of there being only one star, as formerly supposed, there were really two stars so close together that in an ordinary six-inch telescope, such as he had used, they appeared to be one. He inferred also that one of the pair must be a good deal brighter than the other, because at the beginning the change in brightness was less than at the end. This surmise was soon afterward fully verified by Mr. S. W. Burnham with the eighteen and one half inch equatorial of the Dearborn Observatory at Chicago, revealing a close and unequal double star which would have remained unresolved had he used a less powerful instrument.

This Sherburne Wesley Burnham is the most successful discoverer of double stars who has ever lived. “The extreme acuteness of vision,” says Professor John Fraser, “which enables one to prosecute such research with the highest success is a very rare gift; and the discovery of close doubles, as in his case, is its severest test. To measure a star—that is, to ascertain by means of the micrometer the distance and position angle of the companion with reference to the principal star—is one thing, and to find new and close doubles is a very different thing. Baron Dembowski, the most noted measurer of double stars, had no success as a discoverer, and confessed his inability to find new doubles. When, however, a new double had been found by another observer, and the distance and position angle of the companion approximately estimated, he could readily find and accurately measure it. When Mr. Asaph Hall, in 1877, had found the two satellites of Mars and described their positions, it was not difficult for any astronomer who had access to a large Clark telescope to find them and see all that Mr. Hall had seen. The whole difficulty was in seeing them for the first time. Besides the ability to see a difficult object, there is required an intelligence and experimental knowledge of the subject, which are as rare as the visual faculty itself. Some of the lower animals have more acute vision than human beings; but they do not know all they see, or understand relations to other facts. They have plenty of sight, but they lack insight. Mr. Burnham’s powers in both these respects is extraordinary.”

At the Cape of Good Hope Observatory remarkable observations of double stars have been recorded. Sir David Gill, the director, says:—“At the Cape Observatory, as has always been the case elsewhere, the subject of double star measurement on any great scale waited for the proper man to undertake it. There is no instance, so far as I know, of a long and valuable series of double star discovery and observation made by a mere assistant acting under orders. It is a special faculty, an inborn capacity, a delight in the exercise of exceptional acuteness of eyesight and natural dexterity, coupled with the gift of imagination as to the true meaning of what he observes, that imparts to the observer the requisite enthusiasm for double star observing. No amount of training or direction could have created the Struves, a Dawes or a Dembowski. The great double star observer is born, not made, and I believe that no extensive series of double star discovery and measurement will ever emanate from a regular observatory through successive directorates unless men are specially selected who have previously distinguished themselves in that field of work, and who were originally driven to it from sheer compulsion of inborn taste.”

The Eye of a Naturalist.

It is sometimes said that the faculty of observation is a special gift with limitations, that the naturalist sees bones, feathers, shells because he is looking for them, while the armorer or the engineer but seldom gives a second glance to anything but guns, girders, or machinery.

To this rule we find striking exceptions. Edward S. Morse, of Salem, Massachusetts, is the foremost American expert in Japanese pottery. As a youth he was a railroad draughtsman in Portland, Maine, where his ambidexterity with the pencil and his discoveries in natural history brought him to the notice of Louis Agassiz. As a boy he was greatly interested in the shells of his native State; before he left school he had discovered and described a new species of land snail, Helix asteriscus, which the older naturalists had regarded as the young state of another and well-known species. At the same time he determined the distinct character of a most minute species, Helix minutissima, which had been described as such thirty years before, but which the later authorities had believed to be the young of another species. This faculty for discrimination led him to demonstrate a new bone in the ankle of birds which Huxley, and others, had supposed to be a process and not a separate bone. This discovery added another to the many reptilian characters which have been disclosed in the anatomy of birds. He also established beyond question that the brachiopods, always believed to be mollusks, are not mollusks at all, but are related to the worms. In Mr. Morse’s case we have either a man with a universal power of observation, or enjoying distinct faculties of perception, each usually appearing alone in an observer. Noticing a Japanese shooting a bow and arrow one day he took up the study of the attitude of the hand in pulling the bow. His memoir on this subject, with illustrations, has attracted world-wide interest. Pursuing this theme he examined an ancient object of bronze having three prongs, labeled as a bow-puller in European museums, showing that it had no relation whatever with the bow. Keenly susceptible to the beauty and variety of roofing tiles in Europe and the East, he has for the first time given them classification, and shown their ethnological significance. While teaching natural history at the University of Tokio he brought together the Japanese pottery now exhibited at the Museum of Fine Arts in Boston, unsurpassed as a collection in the world. His eye was as sharp in reading a potter’s mark, however worn and blurred, as when as a boy in Maine he defined minute species of land shells.

The Value of Collections.

Altogether commendable is the spirit which leads a boy or girl to collect and arrange shells, common wildflowers, seaweeds, and the diverse minerals brought to light in a railroad cutting. What is thus gathered, compared, and studied will leave a much deeper impression on the memory than what is seen for a moment in a museum or a public garden. And yet, to the profound student the museum is indispensable: he gives weeks or months to the contents of its cases, supplementing what he has learned in the field, by the seashore, in the woods. Take, for example, protective resemblances, one of the most fascinating provinces of natural history. Here is a hornet clear-wing moth. What has made it look like a wasp? Both share the same field of life, and while the wasp does not prey on the moth or in any perceptible way compete with it, the two insects have a vital bond. In its sting the wasp has so formidable and thoroughly advertised a weapon that by closely resembling the wasp the moth, though stingless, is able to live on its neighbor’s reputation, and escape attack from the birds and insects which would devour it if they did not fear that it is a stinging wasp. So far is the resemblance carried that when the moth is caught in the hand it curves its body with an attitude so wasplike as seriously to strain the nerves of its captor.

How came about so elaborate a masquerade? At first, ages ago, there was a faint likeness between the moth and the wasp; any moth in which that likeness was unusually decided had therein an advantage and tended to be in some measure left alone by enemies. In thus escaping it could transmit in an ever-increasing degree, its peculiarities of form and hue to its progeny, until in the rapid succession of insect generations, amid the equally rapid destruction of comparatively unprotected moths, the present striking similarity arose. Instances of this kind abound, forming some of the most attractive exhibits in the American Museum of Natural History of New York, and other great museums. Mr. W. H. Bates, who first explained these resemblances, did so as the result of comparing many various examples preserved in his cabinets at home, although, of course, his memory of habits observed in the field was indispensable. His ample collections enabled him to bring into view at once many captures separated by wide intervals of time and space. It was the opportunity thus afforded of taking a comprehensive survey of resemblances as a whole that led him to think out the underlying reason.

Accidental Observation.

Accident has played a noteworthy part in both discovery and invention. Nathaniel Hayward long ago remarked that sulphur deprives rubber of stickiness. Charles Goodyear one day combined some rubber and sulphur by way of experiment; quite by accident he overturned part of the mixture upon a hot stove. He saw in a moment that heat is essential to make rubber insensible to both heat and cold: he had indeed discovered vulcanization. Examples of this kind abound in the history of every art. As far afield as the war on insect pests in France a priceless discovery was hit upon unsought a few years ago. One autumn the vines were still suffering from phylloxera when a mildew caused by a fungus began to do serious damage to crops. Through the spraying of vines with blue-stone to prevent pilfering of fruit, it was noticed that the fungus was killed, leading to the most telling mode of attack on many of the pests which assail leaves, flowers and fruit.

James Hargreaves once saw a spinning-wheel overturned, when both the wheel and spindle continued to revolve on the floor. As he observed the spindle thus changed from a horizontal to an upright position it occurred to him that if a number of spindles were thus placed, side by side, several threads might be spun at once instead of a single thread. This was the origin of the spinning jenny; an invention which has parallels in the multiple drills, the gang-saws, and other machinery which take a task once executed by a single drill, saw or punch, and simultaneously perform it with ten, twenty, or a hundred drills, saws, or punches.

About thirty years before Josiah Wedgwood laid the foundation of his future eminence, a chance observation gave rise to improvement in the earthenwares of Staffordshire. A potter from Burslem, the centre of the potteries and the birthplace of Wedgwood, in traveling to London on horseback was detained on the road by the inflamed eyes of his horse. Seeing the hostler, the horse-doctor of those times, burn a piece of flint, and, having reduced it to a fine powder, apply it as a specific to the diseased eyes, it occurred to the potter that this beautiful white powder, if combined with the clay used in his craft, might improve the strength and color of his ware. An experiment succeeded, and so began English white ware, since manufactured on an immense scale.

More important than this discovery of a new use for flint powder was the discovery, also accidental, of electro-magnetism by Professor Oersted of Copenhagen. The incident is thus related in a letter to Michael Faraday from Professor Christian Hansteen:—

“Professor Oersted was a man of genius, but he was a very unhappy experimenter; he could not manipulate instruments. He must always have an assistant, or one of his auditors who had easy hands, to arrange the experiment; I have often in this way assisted him. In the eighteenth century there was a general thought that there was a great conformity, and perhaps identity, between the electrical and magnetical forces; and it was a question how to demonstrate it by experiments. Oersted tried to place the wire of his galvanic battery perpendicular (at right angles) over the magnetic needle, but remarked no sensible motion. Once, after the end of his lecture, as he had used a strong galvanic battery to other experiments, he said, ‘Let us now once, as the battery is in activity, try to place the wire parallel with the needle;’ as this was done he was quite struck with perplexity by seeing the needle making a great oscillation (almost at right angles with the magnetic meridian). Then he said, ‘Let us now invert the direction of the current;’ and the needle deviated in the contrary direction. Thus the great detection was made; and it has been said, not without reason, that ‘he tumbled over it by accident.’ He had not before any more idea than any other person that the force should be transversal.”

Granting that many important discoveries thus come about in ways beyond human foresight, accident alone will not produce an invention. As Dr. Ernst Mach reminds us, in every such case the inquirer is obliged to take note of the new fact, to recognize its significance, to detect the part it plays, or can be made to play, in a new structure, or in a novel and sound generalization. What he sees before him, others also have seen, perhaps many times; he is the first to notice it as it deserves to be noticed, simply because he has an eye earnestly desiring to behold just such a fact as this and use it to bridge a gap either in art or explanation.

Let us take a case where an accident, well observed, has meant a golden discovery. One day during a trip on the Thames in a steamer propelled by an Archimedean screw devised by Francis Pettit Smith, the propeller struck an obstacle in the water, so that about one half of the length of the screw was broken off; it was noticed that the vessel immediately shot ahead at a much quickened pace. In consequence of this discovery, a new short screw was fitted to the vessel and with this new propeller the steamer went uniformly faster than before.