But how easily may the just expectations of an inventor be disappointed! Although the principle of artificial draught—the principle which gave to the Novelty such decided superiority in speed—is yet retained in all locomotive engines, the mode of producing this draught in our present engines is far different from that introduced by Ericsson, and was discovered by the merest accident; and so soon was this discovery made, after the successful display of the Novelty engine, that Ericsson had no time to derive the least advantage from its introduction. To him, however, belongs the credit of having disproved the correctness of the once established theory, that it was absolutely necessary that a certain extensive amount of surface should be exposed to the fire, to generate a given quantity of steam.

The remarkable lightness and compactness of the new boiler invented by Ericsson led to the employment of steam in many instances in which it had been previously inapplicable. Among these may be mentioned the steam fire-engine constructed by him in conjunction with Mr. Braithwaite, about the same time with the Novelty, and which excited so much interest in London at the time the Argyle Rooms were on fire. A similar engine of greater power was subsequently constructed by Ericsson and Braithwaite for the King of Prussia, which was mainly instrumental in saving several valuable buildings at a great fire in Berlin. For this invention Ericsson received, in 1842, the large gold medal offered by the Mechanics' Institute of New York for the best plan of a steam fire-engine.

In the year 1833 Ericsson brought before the scientific world in London his invention of the Caloric-Engine, which had been a favorite subject of speculation and reflection with him for many years. From the earliest period of his mechanical labors, he had been in the habit of regarding heat as an agent, which, whilst it exerts mechanical force, undergoes no change. The steam in the cylinder of a steam-engine, after having lifted the weight of the piston, contains just as much heat as it did before leaving the boiler,—minus only the loss by radiation. Yet in the low-pressure engine we turn the steam, after having performed its office, into a condensing-apparatus, where the heat is in a manner annihilated; and in the high-pressure engine we throw it away into the atmosphere.

The acting medium employed in the Caloric-Engine is atmospheric air; and the leading peculiarity of the machine, as originally designed by Ericsson, is, that by means of an apparatus styled the Regenerator the heat contained in the air which escapes from the working cylinder is taken up by the air which enters it at each stroke of the piston and used over and over again.

The machine constructed by Ericsson in London was a working engine of five-horse power, the performance of which was witnessed by many gentlemen of scientific pretensions in that metropolis. Among others, the popular author, Sir Richard Phillips, examined it; and in his "Dictionary of the Arts of Life and of Civilization," he thus notices the result of this experiment:—"The author has, with inexpressible delight, seen the first model machine of five-horse power at work. With a handful of fuel, applied to the very sensible medium of atmospheric air, and a most ingenious disposition of its differential powers, he beheld a resulting action in narrow compass, capable of extension to as great forces as ever can be wielded or used by man." Dr. Andrew Ure went so far as to say that the invention would "throw the name of his great countryman, James Watt, into the shade." Professor Faraday gave it an earnest approval. But, with these and some other eminent exceptions, the scientific men of the day condemned the principle on which the invention was based as unsound and untenable.

The interest which the subject excited did not escape the British Government. Before many days had elapsed, the Secretary of the Home Department, accompanied by Mr. Brunel, the constructor of the Thames Tunnel, made his appearance in the engine-room where the new motive power was in operation. Mr. Brunel, who was at that time somewhat advanced in years, conceived at the outset an erroneous notion of the nature of the new power, which he would not suffer to be corrected by explanations. A discussion sprang up between him and the inventor, which was followed by a long correspondence. The result was, that an unfavorable impression of the invention was communicated to the British Government.

The invention fared little better at the hands of Professor Faraday, from whose efficient advocacy the most favorable results might have been anticipated. This gentleman had announced that he would deliver a lecture on the subject in London, in the spacious theatre of the Royal Institution. The novelty of the invention, combined with the reputation of the lecturer, had attracted a very large audience, including many individuals of eminent scientific attainments. Just half an hour, however, before he was expected to enlighten this distinguished assembly, the celebrated lecturer discovered that he had mistaken the expansive principle which is the very life of the machine. Although he had spent many hours in studying the Caloric-Engine in actual operation, and in testing its absolute force by repeated experiments, Professor Faraday was compelled to inform his hearers, at the very outset, that he did not know why the engine worked at all. He was obliged to confine himself, therefore, to the explanation of the Regenerator, and the process by which the heat is continually returned to the cylinder, and re-employed in the production of force. To this part of the invention he rendered ample justice, and explained it in that felicitous style to which he is indebted for the reputation he deservedly enjoys, as the most agreeable and successful lecturer in England.

Other causes than the misconception of a Brunel and a Faraday operated to retard the practical success of this beautiful invention. The high temperature which it was necessary to keep up in the circulating medium of the engine, and the consequent oxidation, soon destroyed the pistons, valves, and other working parts. These difficulties the inventor endeavored to remedy, in an engine, which he subsequently constructed, of much larger powers, but without success. His failure in this respect, however, did not deter him from prosecuting his invention. He continued his experiments from time to time, as opportunity permitted, confident that he was gradually, but surely, approaching the realization of his great scheme.

Meanwhile he applied himself with his accustomed energy to the practical working out of another favorite idea. The principle of the Ericsson propeller was first suggested to the inventor by a study of the means employed to propel the inhabitants of the air and deep. He satisfied himself that all such propulsion in Nature is produced by oblique action; though, in common with all practical men, he at first supposed that it was inseparably attended by a loss of power. But when he reflected that this was the principle invariably adopted by the Great Mechanician of the Universe, in enabling the birds, insects, and fishes to move through their respective elements, he knew that he must be in error. This he was soon able to demonstrate, and he became convinced, by a strict application of the laws which govern matter and motion, that no loss of power whatever attends the oblique action of the propelling surfaces applied to Nature's locomotives. After having satisfied himself on the theory of the subject, the first step of the inventor was the construction of a small model, which he tried in the circular basin of a bath in London. To his great delight, so perfectly was his theory borne out in practice, that this model, though less than two feet long, performed its voyage about the basin at the rate of three English miles an hour.

The next step in the invention was the construction of a boat forty feet long, eight feet beam, and three feet draught of water, with two propellers, each of five feet three inches in diameter. So successful was this experiment, that, when steam was turned on the first time, the boat at once moved at a speed of upwards of ten miles an hour, without a single alteration being requisite in her machinery. Not only did she attain this considerable speed, but her power to tow larger vessels was found to be so great that schooners of one hundred and forty tons' burden were propelled by her at the rate of seven miles an hour; and the American packet-ship Toronto was towed in the river Thames by this miniature steamer at the rate of more than five English miles an hour. This feat excited no little interest among the boatmen of the Thames, who were astonished at the sight of this novel craft moving against wind and tide without any visible agency of propulsion, and, ascribing to it some supernatural origin, united in giving it the name of the Flying Devil. But the engineers of London Hoarded the experiment with silent neglect; and the subject, when laid before the Lords of the British Admiralty, failed to attract any favorable notice from that august body.

Perceiving its peculiar and admirable fitness for ships of war, Ericsson was confident that their Lordships would at once order the construction of a war-steamer on the new principle. He invited them, therefore, to take an excursion in tow of his experimental boat. Accordingly, the gorgeous and gilt Admiralty Barge was ordered up to Somerset House, and the little steamer was lashed along-side. The barge contained Sir Charles Adam, Senior Lord of the Admiralty,—Sir William Simonds, Chief Constructor of the British Navy,—Sir Edward Parry, the celebrated Arctic navigator,—Captain Beaufort, the Chief of the Topographical Department of the British Admiralty,—and others of scientific and naval distinction.

In the anticipation of a severe scrutiny from so distinguished a personage as the Chief Constructor of the British Navy, the inventor had carefully prepared plans of his new mode of propulsion, which were spread on the damask cloth of the magnificent barge. To his utter astonishment, as we may well imagine, this scientific gentleman did not appear to take the slightest interest in his explanations. On the contrary, with those expressive shrugs of the shoulder and shakes of the head which convey so much to the bystander without absolutely committing the actor,—with an occasional sly, mysterious, undertone remark to his colleagues,—he indicated very plainly, that, though his humanity would not permit him to give a worthy man cause for so much unhappiness, yet that "he could, an if he would," demonstrate by a single word the utter futility of the whole invention.

Meanwhile the little steamer, with her precious charge, proceeded at a steady progress of ten miles an hour, through the arches of the lofty Southwark and London bridges, towards Limehouse, and the steam-engine manufactory of the Messrs. Seaward. Their Lordships having landed, and inspected the huge piles of ill-shaped cast-iron, misdenominated marine engines, intended for some of His Majesty's steamers, with a look at their favorite propelling—apparatus, the Morgan paddle-wheel, they reembarked, and were safely returned to Somerset House by the disregarded, noiseless, and unseen propeller of the new steamer.

On parting, Sir Charles Adam, with a sympathizing air, shook the inventor cordially by the hand, and thanked him for the trouble he had been at in showing him and his friends this interesting experiment, adding that he feared he had put himself to too great an expense and trouble on the occasion. Notwithstanding this somewhat ominous finale of the day's excursion, Ericsson felt confident that their Lordships could not fail to perceive the great importance of the invention. To his surprise, however, a few days afterwards, a friend put into his hands a letter written by Captain Beaufort, at the suggestion, probably, of the Lords of the Admiralty, in which that gentleman, who had himself witnessed the experiment, expressed regret to state that their Lordships had certainly been very much disappointed at its result. The reason for the disappointment was altogether inexplicable to the inventor; for the speed attained at this trial far exceeded anything that had ever been accomplished by any paddle-wheel steamer on so small a scale.

An accident soon relieved his astonishment, and explained the mysterious givings-out of Sir William Simonds on the day of the excursion. The subject having been started at a dinner-table where a friend of Ericsson's was present, Sir William ingeniously and ingenuously remarked, that, "even if the propeller had the power of propelling a vessel, it would be found altogether useless in practice, because, the power being applied in the stern, it would be absolutely impossible to make the vessel steer." It may not be obvious to every one how our naval philosopher derived his conclusion from his premises; but his hearers doubtless readily acquiesced in the oracular proposition, and were much amused at the idea of undertaking to steer a vessel when the power was applied in her stern.

But we may well excuse the Lords of the British Admiralty for exhibiting no interest in the invention, when we reflect that the engineering corps of the empire were arrayed in opposition to it,—alleging that it was constructed upon erroneous principles, and full of practical defects, and regarding its failure as too certain to authorize any speculations even as to its success. The plan was specially submitted to many distinguished engineers, and was publicly discussed in the scientific journals; and there was no one but the inventor who refused to acquiesce in the truth of the numerous demonstrations proving the vast loss of mechanical power which must attend this proposed substitute for the old-fashioned paddle-wheel.

While opposed by such a powerful array of English scientific wisdom, the inventor had the satisfaction of submitting his plan to a citizen of the New World, Mr. Francis B. Ogden,—for many years Consul of the United States at Liverpool,—who was able to understand its philosophy and appreciate its importance. Though not an engineer by profession, Mr. Ogden was distinguished for his eminent attainments in mechanical science, and is entitled to the honor of having first applied the important principle of the expansive power of steam, and of having originated the idea of employing right-angular cranks in marine engines. His practical experience and long study of the subject—for he was the first to stem the waters of the Ohio and Mississippi, and the first to navigate the ocean by the power of steam alone—enabled him at once to perceive the truth of the inventor's demonstrations. And not only did he admit their truth, but he also joined Ericsson in constructing the experimental boat to which we have alluded, and which the inventor launched into the Thames with the name of the "Francis B. Ogden," as a token of respect to his Transatlantic friend.

Other circumstances soon occurred which consoled the inventor for his disappointment in the rejection of the propeller by the British Admiralty. The subject had been brought to the notice of an officer of the United States navy. Captain Robert F. Stockton, who was at that time on a visit to London, and who was induced to accompany him in one of his experimental excursions on the Thames. Captain Stockton is entitled to the credit of being the first naval officer who heard, understood, and dared to act upon the suggestions of Ericsson, as to the application of the propeller to ships of war. At the first glance, he saw the important bearings of the invention; and his acute judgment enabled him at once to predict that it was destined to work a revolution in naval warfare. After making a single trip in the experimental steamboat, from London Bridge to Greenwich, he ordered the inventor to build for him forthwith two iron boats for the United States, with steam-machinery and propeller on the plan of this rejected invention. "I do not want," said Stockton, "the opinions of your scientific men; what I have seen this day satisfies me." He at once brought the subject before the Government of the United States, and caused numerous plans and models to be made, at his own expense, explaining the peculiar fitness of the invention for ships of war. So completely persuaded was he of its great importance in this aspect, and so determined that his views should be carried out, that he boldly assured the inventor that the Government of the United States would test the propeller on a large scale; and so confident was Ericsson that the perseverance and energy of Captain Stockton would sooner or later accomplish what he promised, that he at once abandoned his professional engagements in England, and came to the United States, where he fixed his residence in the city of New York. This was in the year 1839.

Circumstances delayed, for some two years, the execution of their plan. With the change of the Federal Administration, Stockton was first able to obtain a favorable hearing; and having at length received the necessary authority, the Princeton was built under his superintendence, from the designs of Ericsson. She was completed and ready for sea early in 1844, when she was pronounced by Stockton "the cheapest, fastest, and most certain ship of war in the world."

In this vessel, in addition to the propeller, Ericsson introduced his semicylindrical steam-engine, a beautiful invention, so compact that it occupied only one-eighth of the bulk of the British marine engine of corresponding power, and was placed more than four feet below the water-line. The boilers were also below the water-line, having a peculiar heating-apparatus attached which effected a great saving of fuel, and with their furnaces and flues so constructed as to burn anthracite as well as bituminous coal. Instead of the ordinary tall smoke-pipe,—an insuperable objection to a steamer as a ship of war,—he constructed a smoke-pipe upon the principle of the telescope, which could be elevated or depressed at pleasure; and in order to provide a draught independent of the height of the smoke-pipe, he placed centrifugal blowers in the bottom of the vessel, which were worked by separate small engines,—an arrangement originally applied by him to marine engines in the steam-packet Corsair in 1831. Thus the steam-machinery of the Princeton fulfilled the most important requisites for a war-steamer, combining lightness, compactness, simplicity, and efficiency, and being placed wholly out of reach of the enemy's fire.

The armament of the ship also exhibited many peculiarities. "By the application of the various arts to the purposes of war on board of the Princeton," says Captain Stockton, in his report to the Navy Department, "it is believed that the art of gunnery for sea-service has, for the first time, been reduced to something like mathematical certainty. The distance to which the guns can throw their shot at every necessary angle of elevation has been ascertained by a series of careful experiments. The distance from the ship to any object is readily ascertained with an instrument on board, contrived for that purpose, by an observation which it requires but an instant to make, and by inspection without calculation. By self-acting locks, the guns can be fired accurately at the necessary elevation,—no matter what the motion of the ship may be." The instruments here referred to, namely, the Distance-Instrument and the Self-Acting Gun-Lock, and also the wrought-iron gun-carriage, by means of which Captain Stockton's enormous guns were readily handled and directed, all were the productions of Ericsson's fertile mechanical genius.

A committee of the American Institute, by whom this remarkable vessel was examined, thus concluded their report:—"Your Committee take leave to present the Princeton as every way worthy the highest honors of the Institute. She is a sublime conception, most successfully realized,—an effort of genius skilfully executed,—a grand unique combination, honorable to the country, as creditable to all engaged upon her. Nothing in the history of mechanics surpasses the inventive genius of Captain Ericsson, unless it be the moral daring of Captain Stockton, in the adoption of so many novelties at one time." We may add that in the Princeton was exhibited the first successful application of screw-propulsion to a ship of war, and that she was the first steamship ever built with the machinery below the water-line and out of the reach of shot.

Ericsson spent the best part of two years in his labors upon the Princeton. Besides furnishing the general plan of the ship and supplying her in every department with his patented improvements, he prepared, with his own hand, the working-drawings for every part of the steam-machinery, propelling-apparatus, and steering-apparatus in detail, and superintended their whole construction and arrangement, giving careful and exact instructions as to the most minute particulars. In so doing, he was compelled to make frequent journeys from New York to Sandy Hook and Philadelphia, involving no small amount of trouble and expense. For the use of his patent rights in the engine and propeller, he had, at the suggestion of Captain Stockton, refrained from charging the usual fees, consenting to accept, as full satisfaction, whatever the Government, after testing the inventions, should see fit to pay. He never imagined, however, that his laborious services as engineer were to go unrequited, or that his numerous inventions and improvements, unconnected with the engine and propeller, were to be furnished gratuitously. Yet, when, after the Princeton, as we have seen, had been pronounced on all hands a splendid success, Ericsson presented his bill to the Navy Department,—not for the patent-fees in question, but for the bare repayment of his expenditures, and compensation for his time and labor in the service of the United States,—he was informed that his claim could not be allowed; it could not be recognized as a "legal claim." It was not denied that the services alleged had been rendered,—that the work for which compensation was asked had been done by Ericsson, and well done,—nor that the United States were in the enjoyment of the unpaid results of his labor and invention. A claim based upon such considerations might, it would seem, have been brought within the definition of a legal claim. But if not admissible under the strict rules of the Navy Department, it was certainly an equitable demand against the United States; and Ericsson could not believe that the representatives of the great American people would stand upon technicalities. He accordingly made a direct appeal to them in a Memorial to Congress.

We may as well here give the further history of this claim. It met with the usual delays and obstructions that private claims, having nothing but their intrinsic merits to support them, are compelled to encounter. It called forth the usual amount of legislative pettifogging. Session after session passed away, and still it hung between the two Houses of Congress, until the very time which had elapsed since it was first presented began to be brought up as an argument against it. At length, when Congress established the Court of Claims, a prospect opened of bringing it to a fair hearing and a final decision. It was submitted to that tribunal six years ago. The Court decided in its favor,—the three judges (Gilchrist, Scarborough, and Blackford) being unanimous in their judgment. A bill directing its payment was reported to the Senate,—and there it is still. Although favorably reported upon by two committees at different sessions, and once passed by the Senate, without a vote recorded against it, it has never yet got through both Houses of Congress. For furnishing this Government with the magnificent war-steamer which was pronounced by Captain Stockton "the cheapest, fastest, and most certain ship of war in the world," Ericsson has never been paid a dollar. It remains to be seen whether the present Congress will permit this stain upon the national good faith to continue. If it does, its "votes of thanks" are little better than a mockery.

The efficiency and utility of the propeller having been established beyond a doubt, it went at once into extensive use. But the inventor was again disappointed in his just expectation of reaping an adequate pecuniary benefit from his exertions. Upon the strength of some attempts at screw-propulsion,—made and abandoned by various experimenters,—which had never resulted, and probably never would have resulted, in any practical application, rival machines, which conflicted with Ericsson's patent, soon made their appearance. A long litigation followed, during which all attempts to collect patent-fees were necessarily suspended; and the result was, that the invention was virtually abandoned to the public. But no one can take from Ericsson the honor of having first introduced the screw-propeller into actual use, and demonstrated its value,—an honor which is now freely accorded to him by the highest scientific authorities at home and abroad.

Although the first five years of his American experience had been less profitable, in a pecuniary sense, than he had anticipated, he continued to reside in the city of New York, where he found an ample field for the exercise of his great powers in the line of his profession. He planned the war-steamer Pomone, the first screw-vessel introduced into the French navy. He planned revenue-cutters for the United States Government, taking care always to have his contracts so distinctly made that no question could again arise as to his "legal claim." He invented a useful apparatus for supplying the boilers of sea-going steamers with fresh water. He invented various modifications of the steam-engine.

In the American division of the London Industrial Exhibition of all Nations in 1851, he exhibited the Distance-Instrument, for measuring distances at sea,—the Hydrostatic Gauge, for measuring the volume of fluids under pressure,—the Reciprocating Fluid-Metre, for measuring the quantity of water which passes through pipes during definite periods,—the Alarm-Barometer,—the Pyrometer, intended as a standard measure of temperature, from the freezing-point of water up to the melting-point of iron,—a Rotary Fluid-Metre, the principle of which is the measurement of fluids by the velocity with which they pass through apertures of different dimensions,—and a Sea-Lead, contrived for taking soundings at sea without rounding the vessel to the wind, and independently of the length of the lead-line. For these inventions he received the prize-medal of the Exhibition.

But while thus continually occupied with new enterprises and objects, he did not lose sight of his great idea, the Caloric-Engine. All his spare hours and spare funds were devoted to experiments with the view of overcoming the practical difficulties which stood in the way of its success. Towards the end of the year 1851 he seemed to be on the point of realizing his hopes, having constructed a large stationary engine, which was applied with great success, at the Phoenix Foundry in New York, to the actual work of pumping water. Soon after, through the liberality of Mr. John B. Kitching, a well-known merchant of New York, he was enabled to test the invention on a magnificent scale. A ship of two thousand tons, propelled by the power of caloric-engines, was planned and constructed by him in the short space of seven months, and in honor of the inventor received the name of the "Ericsson."

Every one will remember the interest which this caloric-ship excited throughout the country. She made a trip from New York to Alexandria on the Potomac, in very rough weather, in the latter part of February, 1853. On this trip the engines were in operation for seventy-three hours without being stopped for a moment, and without requiring the slightest adjustment, the consumption of fuel being only five tons in twenty-four hours. At Alexandria she was visited by the President and President elect, the heads of the departments, a large number of naval officers, and many members of both Houses of Congress, and subsequently by the foreign ministers in a body, and by the Legislature of Virginia, then in session. Ericsson was invited by a committee of the Legislature to visit Richmond, as the guest of the State. The Secretary of the Navy recommended, in a special communication to Congress, the passage of a resolution authorizing him to contract for the construction of a frigate of two thousand tons to be equipped with caloric-engines, and to appropriate for this purpose five hundred thousand dollars. This recommendation failed in consequence of the pressure of business at the close of the session.

But notwithstanding the surprise and admiration which this achievement excited in the scientific world, the speed attained was not sufficient to meet the practical exigencies of commerce; and the repetition of the engines on this large scale could not be undertaken at the charge of individuals. Ericsson accordingly wisely devoted himself to perfecting the Calorie-Engine on a small scale, and in 1859 he produced it in a form which has since proved a complete success. It is no longer a subject of experiment, but exists as a perfect, practical machine. More than five hundred of these engines, with cylinders varying from a diameter of six inches to one of forty inches, are now in successful operation. It is applied to purposes of pumping, printing, hoisting, grinding, sawing, turning light machinery, working telegraphic instruments and sewing-machines, and propelling boats. No less than forty daily papers (among which we may mention the "National Intelligencer") are printed by means of this engine. In Cuba it is used for grinding sugar-cane, on Southern plantations for ginning cotton; and there is an endless variety of domestic, agricultural, and mechanical uses to which it may be advantageously applied.

The extent of power attainable by this machine, consistently with its application to practical uses, is not yet precisely defined. Within the limit thus far given to it, its power is certain, uniform, and entirely sufficient. It is not attended with the numerous perils that make the steam-engine so uncomfortable a servant, but is absolutely free from danger. It requires no engineering supervision. It consumes a very small amount of fuel (about one-third of the amount required by the steam-engine) and requires no water. These peculiarities not only make it a very desirable substitute for the steam-engine, but render it available for many purposes to which the steam-engine would never be applied.

In addition to his regular professional avocations, Ericsson was industriously occupied in devising new applications of the Calorie-Engine, when the attempted secession of the Southern States plunged the country into the existing war and struck a blow at all the arts of peace. Ills whole heart and mind were given at once to the support of the Union. Liberal in all his ideas, he is warmly attached to republican institutions, and has a hearty abhorrence of intolerance and oppression in all their forms. His early military education and his long study of the appliances of naval warfare increased the interest with which he watched the progress of events. The abandonment of the Norfolk navy-yard to the Rebels struck him as a disgrace that might have been avoided. He foresaw the danger of a formidable antagonist from that quarter in the steamship which we had so obligingly furnished them. The building of gun-boats with steam-machinery above the water-line—where the first shot from an enemy might render it useless—seemed to him, in view of what he had done and was ready to do again, a very unnecessary error. Knowing thoroughly all the improvements made and making in the war-steamers of England and France, and feeling the liability of their interference in our affairs, he could not appreciate the wisdom of building new vessels according to old ideas. The blockade of the Potomac by Rebel batteries, in the very face of our navy, seemed to him an indignity which need not be endured, if the inventive genius of the North could have fair play.

An impregnable iron gun-boat was, in his judgment, the thing that was needed; and he determined that the plan of such a vessel should be his contribution towards the success of the war. The subject was not a new one to him. He had given it much consideration, and his plan, in all its essential features, had been matured long before. Proposals for iron-clad vessels having been invited by the Navy Department, Ericsson promptly submitted his plans and specifications. Knowing the opposition that novelties always encounter, he had no great expectation that his proposal would be accepted. "I have done my part," said he; "I have offered my plan. It is for the Government to say whether I shall be allowed to carry it out." He felt confident, however, that, if the plan should be brought to the notice of the President, his practical wisdom and sound common sense could not fail to decide in its favor. Fortunately for the country, Ericsson's offer was accepted by the Navy Department. He immediately devoted all his energies to the execution of his task, and the result was the construction of the vessel to which he himself gave the name of the "Monitor." What she is and what she has accomplished, we need not here repeat. Whatever may be her future history, we may safely say, in the words of the New York Chamber of Commerce, that "the floating-battery Monitor deserves to be, and will be, forever remembered with gratitude and admiration."

We rejoice to believe that the merits and services of Ericsson are now fully appreciated by the people of the United States. The thanks of the nation have been tendered to him by a resolution of Congress. The Boston Board of Trade and the New York Chamber of Commerce have passed resolutions expressive of their gratitude. The latter body expressed also their desire that the Government of the United States should make to Captain Ericsson "such suitable return for his services as will evince the gratitude of a great nation." Upon hearing this suggestion, Ericsson, with characteristic modesty, remarked,—"All the remuneration I desire for the Monitor I get out of the construction of it. It is all-sufficient." Nevertheless we think the suggestion well worthy of consideration. In the same spirit of manly independence, he discountenanced the movement set on foot among the merchants of New York for the subscription of a sum of money to be presented to him. He asks nothing but fair remuneration for services rendered,—and that, it is to be hoped, the people will take care that he shall receive.

Ericsson is now zealously at work in constructing six new iron gun-boats on the plan of the Monitor. If that remarkable structure can be surpassed, he is the man to accomplish it. His ambition is to render the United States impregnable against the navies of the world. "Give me only the requisite means," he writes, "and in a very short time we can say to those powers now bent on destroying republican institutions, 'Leave the Gulf with your frail craft, or perish!' I have all my life asserted that mechanical science will put an end to the power of England over the seas. The ocean is Nature's highway between the nations. It should be free; and surely Nature's laws, when properly applied, will make it so."

His reputation as an engineer is worldwide. In 1852 he was made a Knight of the Order of Vasa by King Oscar of Sweden. The following extract from a poem "To John Ericsson" we translate from "Svenska Tidningen," the Government journal of Stockholm. It is eloquently expressive of the pride and admiration with which he is regarded in his native country.

"World-wide his fame, so gracefully adorning His native Sweden with enduring radiance! Not a king's crown could give renown so noble: For his is Thought's great triumph, and the sceptre He wields is over elements his subjects!"

Although now in his sixtieth year, Ericsson has the appearance of a man of forty. He is in the very maturity of a vigorous manhood, and retains all the fire and enthusiasm of youth. He has a frame of iron, cast in a large and symmetrical mould. His head and face are indicative of intellectual power and a strong will. His presence impresses one, at the first glance, as that of an extraordinary man. His bearing is dignified and courteous, with a touch perhaps of military brusquerie in his mode of address. He has a keen sense of humor, a kindly and generous disposition, and a genial and companionable nature. He is a "good hater" and a firm friend. Like all men of strong character and outspoken opinions, he has some enemies; but his chosen friends he "grapples to his heart with hooks of steel."

He is not a mere mechanician, but has great knowledge of men and of affairs, and an ample fund of information on all subjects. His conversation is engaging and instructive; and when he seeks to enlist coperation in his mechanical enterprises, few men can withstand the force of his arguments and the power of his personal magnetism.

Although his earnings have sometimes been large, his heavy expenditures in costly experiments have prevented him from acquiring wealth. Money is with him simply a means of working out new ideas for the benefit of mankind; and in this way he does not scruple to spend to the utmost limit of his resources. He lives freely and generously, but is strictly temperate and systematic in all his habits.

The amount of labor which he is capable of undergoing is astonishing. While engaged in carrying out his inventions, it is a common thing for him to pass sixteen hours a day at his table, in the execution of detailed mechanical drawings, which he throws off with a facility and in a style that have probably never been surpassed. He does not seem to need such recreation as other men pine after. He never cares to run down to the seashore, or take a drive into the country, or spend a week at Saratoga or at Newport. Give him his drawing-table, his plans, his models, the noise of machinery, the clatter of the foundry, and he is always contented. Week in and week out, summer and winter, he works on and on,—and the harder he works, the more satisfied he seems to be. He is as untiring as one of his own engines, which never stop so long as the fire burns. Endowed with such a constitution, it is to be hoped that new triumphs and many years of honor and usefulness are yet before him.

* * * * *

MOVING.

Man is like an onion. He exists in concentric layers. He is born a bulb and grows by external accretions. The number and character of his involutions certify to his culture and courtesy. Those of the boor are few and coarse. Those of the gentleman are numerous and fine. But strip off the scales from all and you come to the same germ. The core of humanity is barbarism. Every man is a latent savage.

You may be startled and shocked, but I am stating fact, not theory. I announce not an invention, but a discovery. You look around you, and because you do not see tomahawks and tattooing you doubt my assertion. But your observation is superficial. You have not penetrated into the secret place where souls abide. You are staring only at the outside layer of your neighbors; just peel them and see what you will find.

I speak from the highest possible authority,—my own. Representing the gentler half of humanity, of respectable birth, tolerable parts, and good education, as tender-hearted as most women, not unfamiliar with the best society, mingling, to some extent, with those who understand and practise the minor moralities, you would at once infer from my circumstances that I was a very fair specimen of the better class of Americans,—and so I am. For one that stands higher than I in the moral, social, and intellectual scale, you will undoubtedly find ten that stand lower. Yet through all these layers gleam the fiery eyes of my savage. I thought I was a Christian, I have endeavored to do my duty to my day and generation; but of a sudden Christianity and civilization leave me in the lurch, and the "old Adam" within me turns out to be just such a fierce Saxon pirate as hurtled down against the white shores of Britain fifteen hundred years ago.

For we have been moving.

People who live in cities and move regularly every year from one good, finished, right-side-up house to another will think I give a very small reason for a very broad fact; but they do not know what they are talking about. They have fallen into a way of looking upon a house only as an exaggerated trunk, into which they pack themselves annually with as much nonchalance as if it were only their preparation for a summer trip to the seashore. They don't strike root anywhere. They don't have to tear up anything. A man comes with cart and horses. There is a stir in the one house,—they are gone;—there is a stir in the other house,—they are settled,—and everything is wound up and set going to run another year. We do these things differently in the country. We don't build a house by way of experiment and live in it a few years, then tear it down and build another. We live in a house till it cracks, and then we plaster it over; then it totters, and we prop it up; then it rocks, and we rope it down; then it sprawls, and we clamp it; then it crumbles, and we have a new underpinning,—but keep living in it all the time. To know what moving really means, you must move from just such a rickety-rackety old farmhouse, where you have clung and grown like a fungus ever since there was anything to grow,—where your life and luggage have crept into all the crevices and corners, and every wall is festooned with associations thicker than the cobwebs, though the cobwebs are pretty thick,—where the furniture and the pictures and the knick-knacks are so become a part and parcel of the house, so grown with it and into it, that you do not know they are chiefly rubbish till you begin to move them and they fall to pieces, and don't know it then, but persist in packing them up and carrying them away for the sake of auld lang syne, till, set up again in your new abode, you suddenly find that their sacredness is gone, their dignity has degraded into dinginess, and the faded, patched chintz sofa, that was not only comfortable, but respectable, in the old wainscoted sitting-room, has suddenly turned into "an object," when lang syne goes by the board and the heirloom is incontinently set adrift. Undertake to move from this tumble-down old house, strewn thick with the dbris of many generations, into a tumble-up, peaky, perky, plastery, shingly, stary new one, that is not half finished, and never will be, and good enough for it, and you will perhaps comprehend how it is that I find a great crack in my life. On the farther side are prosperity, science, literature, philosophy, religion, society, all the refinements, and amenities, and benevolences, and purities of life,—in short, all the arts of peace, and civilization, and Christianity,—and on this side—moving. You will also understand why that one word comprises, to my thinking, all the discomforts short of absolute physical torture that can be condensed into the human lot. Condensed, did I say? If it were a condensed agony, I could endure it. One great, stunning, overpowering blow is undoubtedly terrible, but you rally all your fortitude to meet and resist it, and when it is over it is over and the recuperative forces go to work; but a trouble that worries and baffles and pricks and rasps you, that penetrates into all the ramifications of your life, that fills you with profound disgust, and fires you with irrepressible fury, and makes of you an Ishmaelite indeed, with your hand against every man and every man's hand against you,—ah! that is the experimentum crucis. Such is moving, in the country,—not an act, but a process,—not a volition, but a fermentation.

We will say that the first of September is the time appointed for the transit. The day approaches. It is the twenty-ninth of August. I prepare to take hold of the matter in earnest. I am nipped in the bud by learning that the woman who was to help about the carpets cannot come, because her baby is taken with the croup. I have not a doubt of it. I never knew a baby yet that did not go and have the croup, or the colic, or the cholera infantum, just when it was imperatively necessary that it should not have them. But there is no help for it. I shudder and bravely gird myself for the work. I tug at the heavy, bulky, unwieldy carpets, and am covered with dust and abomination. I think carpets are the most untidy, unwholesome nuisances in the whole world. It is impossible to be clean with them under your feet. You may sweep your carpet twenty times and raise a dust on the twenty-first. I am sure I heard long ago of some new fashion that was to be introduced,—some Italian style, tiles, or mosaic-work, or something of the sort. I should welcome anything that would dispense with these vile rags. I sigh over the good old sanded floors that our grandmothers rejoiced in,—and so, apotheosizing the past and anathematizing the present, I pull away, and the tacks tear my fingers, and the hammer slips and lets me back with a jerk, and the dust fills my hair and nose and eyes and mouth and lungs, and my hands grow red and coarse and ragged and sore and begrimed, and I pull and choke and cough and strangle and pull.

So the carpets all come up and the curtains all come down. The bureaus march out of the chamber-windows and dance on a tight-rope down into the yard below. The chairs are set at "heads and points." The clothes are packed into the trunks. The flour and meal and sugar, all the wholesale edibles, are carted down to the new house and stored. The forks are wrapped up and we eat with our fingers, and have nothing to eat at that. Then we are informed that the new house will not be ready short of two weeks at least. Unavoidable delays. The plasterers were hindered; the painters misunderstood orders; the paperers have defalcated, and the universe generally comes to a pause. It is no matter in what faith I was nurtured, I am now a believer in total depravity. Contractors have no conscience; masons are not men of their word; carpenters are tricky; all manner of cunning workmen are bruised reeds. But there is nothing to do but submit and make the best of it,—a horrible kind of mechanism. We go forthwith into a chrysalis state for two weeks. The only sign of life is an occasional lurch towards the new house, just sufficient to keep up the circulation. One day I dreamily carry down a basket of wine-glasses. At another time I listlessly stuff all my slippers into a huge pitcher and take up the line of march. Again a bucket is filled with tea-cups, or I shoulder the fire-shovel. The two weeks drag themselves away, and the cry is still, "Unfinished!" To prevent petrifying into a fossil remain, or relapsing into primitive barbarism, or degenerating into a dormouse, I rouse my energies and determine to put my own shoulder to the wheel and see if something cannot be accomplished. I rise early in the morning and walk to Dan, to hire a painter who is possessed of "gumption," "faculty." Arrived in Dan, I am told that he is in Beersheba. Nothing daunted, I take a short cut across the fields to Beersheba, bearding manifold dangers from rickety stone-walls, strong enough to keep women in, but not strong enough to keep bears, bulls, and other wild beasts out,—toppling enough to play the mischief with draperies, but not toppling enough to topple over when urgently pressed to do so. But I secure my man, and remember no more my sorrow of bulls and stones for joy at my success. From Beersheba I proceed to Padan-aram to buy seven pounds of flour, thence to Galilee of the Gentiles for a pound of cheese, thence to the land of Uz for a smoked halibut, thence to the ends of the earth for a lemon to make life tolerable,—and the days hobble on.

"The flying gold of the ruined woodlands" drives through the air, the signal is given, and there is no longer "quiet on the Potomac." The unnatural calm gives way to an unearthly din. Once more I bring myself to bear on the furniture and the trumpery, and there is a small household whirlpool. All that went before "pales its ineffectual fires." Now comes the strain upon my temper, and my temper bends, and quivers, and creaks, and cracks. Ithuriel touches me with his spear; all the integuments of my conventional, artificial, and acquired gentleness peel off, and I stand revealed a savage. Everything around me sloughs off its usual habitude and becomes savage. Looking-glasses are shivered by the dozen. A bit is nicked out of the best China sugar-bowl. A pin gets under the matting that is wrapped around the centre-table and jags horrible hieroglyphics over the whole polished surface. The bookcase that we are trying to move tilts, and trembles, and goes over, and the old house through all her frame gives signs of woe. A crash detonate on the stairs brings me up from the depths of the closet where I am burrowing. I remember seeing Petronius disappear a moment ago with my lovely and beloved marble Hebe in his arms. I rush rampant to the upper landing in time to see him couchant on the lower. "I have broken my leg," roars Petronius, as if I cared for his leg. A fractured leg is easily mended; but who shall restore me the nose of my nymph, marred into irremediable deformity and dishonor?

Occasionally a gleam of sunshine shoots athwart the darkness to keep me back from rash deeds. Behind the sideboard I find a little cross of dark, bright hair and gold and pearls, that I lost two years ago and would not be comforted. O happy days woven in with the dark, bright hair! O golden, pearly days, come back to me again! "Never mind your gewgaws," interposes real life; "what is to be done with the things in this drawer?" Lying atop of a heap of old papers in the front-yard, waiting the match that is to glorify them into flame, I find a letter that mysteriously disappeared long since and caused me infinite alarm lest indelicate eyes might see it and indelicate hands make ignoble use of its honest and honorable meaning. I learn also sundry new and interesting facts in mechanics. I become acquainted for the first time with the modus operandi of "roller-cloths." I never understood before how the roller got inside the towel. It was one of those gentle domestic mysteries that repel even while they invite investigation. I shall not give the result of my discovery to the public. If you wish very much to find out, you can move, as I did.

But the rifts of sunshine disappear, the clouds draw together and close in. The savage walks abroad once more, and I go to bed tired of life.

I have scarcely fallen asleep, when I am reluctantly, by short and difficult stages, awakened. A rumbling, grating, strident noise first confuses, then startles me. Is it robbers? Is it an earthquake? Is it the coming of fate? I lie rigid, bathed in a cold perspiration. I hear the tread of banditti on the moaning stairs. I see the flutter of ghostly robes by the uncurtained windows. A chill, uncanny air rushes in and grips at my damp hair. I am nerved by the extremity of my terror. I will die of anything but fright. I jerk off the bedclothes, convulse into an upright posture, and glare into the darkness. Nothing. I rise softly, creep cautiously and swiftly over the floor, that always creaked, but now thunders at every footfall. A light gleams through the open door of the opposite room whence the sound issues. A familiar voice utters an exclamation which I recognize. It is Petronius, the unprincipled scoundrel, who is uncording a bed, dragging remorselessly through innumerable holes the long rope whose doleful wail came near giving me an epilepsy. My savage lets loose the dogs of war. Petronius would fain defend himself by declaring that it is morning. I indignantly deny it. He produces his watch. A fig for his watch! I stake my consciousness against twenty watches, and go to bed again; but Sleep, angry goddess, once repulsed, returns no more. The dawn comes up the sky and confirms the scorned watch. The golden daggers of the morning prick in under my eyelids, and Petronius introduces himself upon the scene once more to announce, that, if I don't wish to be corded up myself, I must abdicate that bed. The threat does not terrify me. Indeed, nothing at the moment seems more inviting than to be corded up and let alone; but duty still binds me to life, and, assuring Petronius that the just law will do that service for him, if he does not mend his ways, I slowly emerge again into the world,—the dreary, chaotic world,—the world that is never at rest.

And there is hurrying to and fro, and a clang of many voices, and the clatter of much crockery, and a lifting, and balancing, and battering against walls and curving around corners, and sundry contusions, and a great waste of expletives, and a loading of wagons, and a driving of patient oxen back and forth with me generally on the top of the load, steadying a basket of eggs with one foot, keeping a tin can of something from upsetting with the other, and both arms stretched around a very big and very square picture-frame that knocks against my nose or my chin every time the cart goes over a stone or drops into a rut, and the wind threatening to blow my hat off, and blowing it off, and my "back-hair" tumbling down,—and the old house is at last despoiled. The rooms stand bare and brown and desolate. The sun, a hand-breadth above the horizon, pours in through the unblinking windows. The last load is gone. The last man has departed. I am left alone to lock up the house and walk over the hill to the new home. Then, for the first time, I remember that I am leaving. As I pass through the door of my own room, not regretfully, I turn. I look up and down and through and through the place where I shall never rest again, and I rejoice that it is so. As I stand there, with the red, solid sunshine lying on the floor, lying on the walls, unfamiliar in its new profusion, the silence becomes audible. In the still October evening there is an effort in the air. The dumb house is striving to find a voice. I feel the struggle of its insensate frame. The old timbers quiver with the unusual strain. The strong, blind, vegetable energy agonizes to find expression, and, wrestling like a pinioned giant, the soul of matter throws off the weight of Its superincumbent inertia. Slowly, gently, most sorrowfully through the golden air cleaves a voice that is somewhat a wail, yet not untuned by love. Inarticulate at first, I catch only the low mournfulness; but it clears, it concentrates, it murmurs into cadence, it syllables into intelligence, and thus the old house speaks:—

"Child, my child, forward to depart, stay for one moment your eager feet. Put off from your brow the crown which the sunset has woven, and linger yet a little longer in the shadow which enshrouds me forever. I remember, in this parting hour, the day of days which the tremulous years bore in their bosom,—a day crimson with the woodbine's happy flush and glowing with the maple's gold. On that day a tender, tiny life came down, and stately Silence fled before the pelting of baby-laughter. Faint memories of far-off olden time were softly stirred. Blindly thrilled through all my frame a vague, dim sense of swelling buds, and singing-birds, and summer-gales,—of the purple beauty of violets, the smells of fragrant earth, and the sweetness of summer dews and darks. Many a harvest-moon since then has filled her yellow horn, and queenly Junes crowned with roses have paled before the sternness of Decembers. But Decembers and Junes alike bore royal gifts to you,—gifts to the busy brain and the awakening heart. In dell and copse and meadow and gay green-wood you drank great draughts of life. Yet, even as I watched, your eyes grew wistful. Your lips framed questions for which the Springs found no reply, and the sacred mystery of living brought its sweet, uncertain pain. Then you went away, and a shadow fell. A gleam passed out of the sunshine and a note from the robin's song. The knights that pranced on the household hearth grew faint and still, and died for want of young eyes to mark their splendor. But when your feet, ever and anon, turned homeward, they used a firmer step, and I knew, that, though the path might be rough, you trod it bravely. I saw that you had learned how doing is a nobler thing than dreaming, yet kept the holy fire burning in the holy place. But now you go, and there will be no return. The stars are faded from the sky. The leaves writhe on the greensward. The breezes wail a dirge. The summer rain is pallid like winter snow. And—O bitterest cup of all!—the golden memories of the past have vanished from your heart. I totter down to the grave, while you go on from strength to strength. The Junes that gave you life brought death to me, and you sorrow not. O child of my tender care, look not so coldly on my pain! Breathe one sigh of regret, drop one tear of pity, before we part!"

The mournful murmur ceased. I am not adamant. My savage crouched out of sight among the underbrush. I think something stirred in the back of my eyes. There was even a suspicion of dampness in front. I thrust my hand in my pocket to have my handkerchief ready in case of a catastrophe. It was an unfortunate proceeding. My pocket was crammed full. I had to push my fingers in between all manner of rubbish, to get at the required article, and when I got hold of it, I had to pull with all my might to get it out, and when it did come, out with it came a tin box of mustard seed, a round wooden box of tooth-powder, a ball of twine, a paper of picture-books, and a pair of gloves. Of course, the covers of both the boxes came off. The seed scattered over the floor. The tooth-powder puffed a white cloud into my face. The ball of twine unrolled and trundled to the other side of the room. I gathered up what I could, but, by the time order was restored and my handkerchief ready for use, I had no use for it. The stirring in the back of my eyes had stopped. The dewiness had disappeared. My savage sprang out from the underbrush and brandished his tomahawk. And to the old house I made answer as a Bushman of Caffraria might, or a Sioux of the Prae-Pilgrimic Age:—

"Old House, hush up! Why do you talk stuff? 'Golden memories' indeed! To hear you, one might suppose you were an ivied castle on the Rhine, and I a fair-haired princess, cradled in the depths of regal luxury, feeding on the blossoms of a thousand generations, and heroic from inborn royalty. 'Tender care'! Did you not wake me in the middle of the night, last summer, by trickling down water on my face from a passing shower? and did I not have to get up at that unearthly hour to move the bed, and step splash into a puddle, and come very near being floated away? Did not the water drip, drip, drip upon my writing-desk, and soak the leather and swell the wood, and stain the ribbon and spoil the paper inside, and all because you were treacherous at the roof and let it? Have you not made a perfect rattery of yourself, yawning at every possible chink and crumbling at the underpinning, and keeping me awake night after night by the tramp of a whole brigade of the Grand Army that slaughtered Bishop Hatto? Whenever a breeze comes along stout enough to make an aspen-leaf tremble, don't you immediately go into hysterics, and rock, and creak, and groan, as if you were the shell of an earthquake? Don't you shrivel at every window to let in the northeasters and all the snow-storms that walk abroad? Whenever a needle, or a pencil, or a penny drops, don't you open somewhere and take it in? 'Golden memories'! Leaden memories! Wooden memories! Madden memories!"

My savage gave a war-whoop. I turned scornfully. I swept down the staircase. I banged the front-door. I locked it with an accent, and marched up the hill. A soft sighing breathed past me. I knew it was the old house mourning for her departing child. The sun had disappeared, but the western sky was jubilant in purple and gold. The cool evening calmed me. The echoes of the war-whoop vibrated almost tenderly along the hushed hillside. I paused on the summit of the hill and looked back. Down in the valley stood the sorrowful house, tasting the first bitterness of perpetual desolation. The maples and the oaks and the beech-trees hung out their flaming banners. The pond lay dark in the shadow of the circling hills. The years called to me,—the happy, sun-ripe years that I had left tangled in the apple-blossoms, and moaning among the pines, and tinkling in the brook, and floating in the cups of the water-lilies. They looked up at me from the orchard, dark and cool. They thrilled across from the hill-tops, glowing still with the glowing sky. I heard their voice by the lilac-bush. They smiled at me under the peach-trees, and where the blackberries had ripened against the southern wall. I felt them once more in the clover-smells and the new-mown hay. They swayed again in the silken tassels of the crisp, rustling corn. They hummed with the bees in the garden-borders. They sang with the robins in the cherry-trees, and their tone was tender and passing sweet. They besought me not to cast away their memory for despite of the black-browed troop whose vile and sombre robes had mingled in with their silver garments. They prayed me to forget, but not all. They minded me of the sweet counsel we had taken together, when summer came over the hills and walked by the watercourses. They bade me remember the good tidings of great joy which they had brought me when my eyes were dim with unavailing tears. My lips trembled to their call. The war-whoop chanted itself into a vesper. A happy calm lifted from my heart and quivered out over the valley, and a comfort settled on the sad old house as I stretched forth my hands and from my inmost soul breathed down a Benedicite!

* * * * *

METHODS OF STUDY IN NATURAL HISTORY.

It may seem to some of my readers that I have wandered from my subject and forgotten the title of these articles, which purport to be a series of papers on "Methods of Study in Natural History." But some idea of the progress of Natural History, of its growth as a science, of the gradual evolving of general principles out of a chaotic mass of facts, is a better aid to the student than direct instruction upon special modes of investigation; and it is with the intention of presenting the study of Natural History from this point of view that I have chosen my title.

I have endeavored thus far to show how scientific facts have been systematized so as to form a classification that daily grows more true to Nature, in proportion as its errors are corrected by a more intimate acquaintance with the facts; but I will now attempt a more difficult task, and try to give some idea of the mental process by which facts are transformed into scientific truth. I fear that the subject may seem very dry to my readers, and I would again ask their indulgence for details absolutely essential to my purpose, but which would indeed be very wearisome, did they not lead us up to an intelligent and most significant interpretation of their meaning.

I should be glad to remove the idea that science is the mere amassing of facts. It is true that scientific results grow out of facts, but not till they have been fertilized by thought The facts must be collected, but their mere accumulation will never advance the sum of human knowledge by one step;—it is the comparison of facts and their transformation into ideas that lead to a deeper insight into the significance of Nature. Stringing words together in incoherent succession does not make an intelligible sentence; facts are the words of God, and we may heap them together endlessly, but they will teach us little or nothing till we place them in their true relations and recognize the thought that binds them together as a consistent whole.

I have spoken of the plans that lie at the foundation of all the variety of the Animal Kingdom as so many structural ideas which must have had an intellectual existence in the Creative Conception independently of any special material expression of them. Difficult though it be to present these plans as pure abstract formulae, distinct from the animals that represent them, I would nevertheless attempt to do it, in order to show how the countless forms of animal life have been generalized into the few grand, but simple intellectual conceptions on which all the past populations of the earth as well as the present creation are founded. In such attempts to divest the thought of its material expression, especially when that expression is multiplied in such thousand-fold variety of form and color, our familiarity with living animals is almost an obstacle to our success. For I shall hardly be able to allude to the formula of the Radiates, for instance,—the abstract idea that includes all the structural possibilities of that division of the Animal Kingdom,—without recalling to my readers a Polyp or a Jelly-Fish, a Sea-Urchin or a Star-Fish. Neither can I present the structural elements of the Mollusk plan, without reminding them of an Oyster or a Clam, a Snail or a Cuttle-Fish,—or of the Articulate plan, without calling up at once the form of a Worm, a Lobster, or an Insect,—or of the Vertebrate plan, without giving it the special character of Fish, Reptile, Bird, or Mammal. Yet I insist that all living beings are but the different modes of expressing these formulae, and that all animals have, within the limits of their own branch of the Animal Kingdom, the same structural elements, though each branch is entirely distinct. If this be true, and if these organic formulae have the precision of mathematical formulae, with which I have compared them, they should be susceptible of the same tests.

The mathematician proves the identity of propositions that have the same mathematical value and significance by their convertibility. If they have the same mathematical quantities, it must be possible to transform them, one into another, without changing anything that is essential in either. The problem before us is of the same character. If, for instance, all Radiates, be they Sea-Anemones, Jelly-Fishes, Star-Fishes, or Sea-Urchins, are only various modes of expressing the same organic formula, each having the sum of all its structural elements, it should be possible to demonstrate that they are reciprocally convertible. This is actually the case, and I hope to be able to convince my readers that it is no fanciful theory, but may be demonstrated as clearly as the problems of the geometer. The naturalist has his mathematics, as well as the geometer and the astronomer; and if the mathematics of the Animal Kingdom have a greater flexibility than those of the positive sciences, and are therefore not so easily resolved into their invariable elements, it is because they have the freedom and pliability of life, and evade our efforts to bring all their external variety within the limits of the same structural law which nevertheless controls and includes them all.

I wish that I could take as the illustration of this statement animals with whose structure the least scientific of my readers might be presumed to be familiar; but such a comparison of the Vertebrates, showing the identity and relation of structural elements throughout the Branch, or even in any one of its Classes, would be too extensive and complicated, and I must resort to the Radiates,—that branch of the Animal Kingdom which, though less generally known, has the simplest structural elements.

I will take, then, for the further illustration of my subject, the Radiates, and especially the class of Echinoderms, Star-Fishes, Sea-Urchins, and the like, both in the fossil and the living types; and though some special description of these animals is absolutely essential, I will beg my readers to remember that the general idea, and not its special manifestations, is the thing I am aiming at, and that, if we analyze the special parts characteristic of these different groups, it is only that we may resolve them back again into the structural plan that includes them all.

I have already in a previous article named the different Orders of this Class in their relative rank, and have compared the standing of the living ones, according to the greater or less complication of their structure, with the succession of the fossil ones. Of the five Orders, Beches-de-Mer, Sea-Urchins, Star-Fishes, Ophiurans, and Crinoids,—or, to name them all according to their scientific nomenclature, Holothurians, Echinoids, Asteroids, Ophiurans, and Crinoids,—the last-named are lowest in structure and earliest in time. Cuvier was the first naturalist who detected the true nature of the Crinoids, and placed them where they belong in the classification of the Animal Kingdom. They had been observed before, and long and laborious investigations had been undertaken upon them, but they were especially baffling to the student, because they were known only in the fossil condition from incomplete specimens; and though they still have their representatives among the type of Echinoderms as it exists at present, yet, partly owing to the rarity of the living specimens and partly to the imperfect condition of the fossil ones, the relation between them was not recognized. The errors about them certainly did not arise from any want of interest in the subject among naturalists, for no less than three hundred and eighty different authors have published their investigations upon the Crinoids, and the books that have been printed about these animals, many of which were written long before their animal nature was suspected, would furnish a library in themselves. The ancients knew little about them. The only one to be found in the European seas resembles the Star-Fish closely, and they called it Asterias; but even Aristotle was ignorant of its true structural relations, and alludes only to its motion and general appearance. Some account of the gradual steps by which naturalists have deciphered the true nature of these lowest Echinoderms and their history in past times may not be without interest, and is very instructive as showing bow such problems may be solved.

In the sixteenth century some stones were found bearing the impression of a star on their surface. They received the name of Trochites, and gave rise to much discussion. Naturalists puzzled their brains about them, called them star-shaped crystals, aquatic plants, corals; and to these last Linnaeus himself, the great authority of the time on all such questions, referred them. Beside these stony stars, which were found in great quantities when attention was once called to them, impressions of a peculiar kind had been observed in the rocks, resembling flowers on long stems, and called "stone lilies" naturally enough, for their long, graceful stems, terminating either in a branching crown or a closer cup, recall the lily tribe among flowers. The long stems of these seeming lilies are divided transversely at regular intervals;—the stem is easily broken at any of these natural divisions, and on each such fragment is stamped a star-like impression resembling those found upon the loose stones or Trochites.

About a century ago, Guettard the naturalist described a curious specimen from Porto Rico, so similar to these fossil lilies of the rocks that he believed they must have some relation to each other. He did not detect its animal nature, but from its long stem and branching crown he called it a marine palm. Thus far neither the true nature of the living specimen, nor of the Trochites, nor of the fossil lilies was understood, but it was nevertheless an important step to have found that there was a relation between them. A century passed away, and Guettard's specimen, preserved at the Jardin des Plantes, waited with Sphinx-like patience for the man who should solve its riddle.

Cuvier, who held the key to so many of the secrets of Nature, detected at last its true structure; he pronounced it to be a Star-Fish with a stem, and at once the three series of facts respecting the Trochites, the fossil lilies, and Guettard's marine palm assumed their true relation to each other. The Troehites were recognized as simply the broken portions of the stem of some of these old fossil Crinoids, and the Crinoids themselves were seen to be the ancient representatives of the present Comatulae and Star-Fishes with stems. So is it often with the study of Nature; many scattered links are collected before the man comes who sees the connection between them and speaks the word that reconstructs the broken chain.

I will begin my comparison of all Echinoderms with an analysis of the Star-Fishes and Sea-Urchins, because I think I can best show the identity of parts between them, notwithstanding the difference in their external form; the Sea-Urchins having always a spherical body, while the Star-Fishes are always star-shaped, though in some the star is only hinted at, sketched out, as it were, in a simply pentagonal outline, while in others the indentations between the rays are very deep, and the rays themselves so intricate in their ramifications as to be broken up into a complete net-work of branches. But under all this variety of outline, our problem remains always the same: to build with the same number of pieces a star and a sphere, having the liberty, however, of cutting the pieces differently and changing their relative proportions. Let us take first the Sea-Urchin and examine in detail all parts of its external structure. I shall say nothing of the internal structure of any of these animals, because it does not affect the comparison of their different forms and the external arrangement of parts, which is the subject of the present article.

On the lower side is the mouth, and we may call that side and all the parts that radiate from it the oral region. On the upper side is a small area to which the parts converge, and which, from its position just opposite the so-called mouth or oral opening, we may call the ab-oral region. I prefer these more general terms, because, if we speak of the mouth, we are at once reminded of the mouth in the higher animals, and in this sense the word, as applied to the aperture through which the Sea-Urchins receive their food, is a misnomer. Very naturally the habit has become prevalent of naming the different parts of animals from their function, and not from their structure; and in all animals the aperture through which food enters the body is called the mouth, though there is not the least structural relation between the organs so designated, except within the limits of each different branch or division. To speak of these opposite regions in the Sea-Urchin as the upper and lower sides would equally mislead us, since, as we have seen, there is, properly speaking, no above and below, no right and left sides, no front and hind extremities in these animals, all parts being evenly distributed around a vertical axis. I will, therefore, although it has been my wish to avoid technicalities as much as possible in these papers, make use of the unfamiliar terms oral and ab-oral regions, to indicate the mouth with the parts diverging from it and the opposite area towards which all these parts converge. [Footnote: When reference is made to the whole structure, including the internal organs as well as the solid parts of the surface, the terms actinal and ab-actinal are preferable to oral and ab-oral.]



The whole surface of the animal is divided by zones,—ten in number, five broader ones alternating with five narrower ones. The five broad zones are composed of large plates on which are the most prominent spines, attached to tubercles that remain on the surface even when the spines drop off after death, and mark the places where the spines have been. The five small zones are perforated with regular rows of holes, and through these perforations pass the suckers or water-tubes which are their locomotive appendages. For this reason these narrower zones are called the ambulacra, while the broader zones intervening between them and supporting the spines are called the interambulacra. Motion, however, is not the only function of these suckers; they are subservient also to respiration and circulation, taking in water, which is conveyed through them into various parts of the body.



The oral aperture is occupied by five plates, which may be called jaws, remembering always that here again this word signifies the function, and not the structure usually associated with the presence of jaws in the higher animals; and each of these jaws or plates terminates in a tooth. Even the mode of eating in these animals is controlled by their radiate structure; for these jaws, evenly distributed about the circular oral aperture, open to receive the prey and then are brought together to crush it, the points meeting in the centre, thus working concentrically, instead of moving up and down or from right to left, as in other animals. From the oral opening the ten zones diverge, spreading over the whole surface, like the ribs on a melon, and converging in the opposite direction till they meet in the small space which we have called the ab-oral region opposite the starting-point.

Here the broad zones terminate in five large plates differing somewhat from those that form the zones in other parts of the body, and called ovarian plates, because the eggs pass out through certain openings in them; while the five narrow zones terminate in five small plates on each of which is an eye, making thus five eyes alternating with five ovarian plates. The centre of this area containing the ovarian plates and the visual plates is filled up with small movable plates closing the space between them. I should add that one of the five ovarian plates is larger than the other four, and has a peculiar structure, long a puzzle to naturalists. It is perforated with minute holes, forming an exceedingly delicate sieve, and this is actually the purpose it serves. It is, as it were, a filter, and opens into a canal which conducts water through the interior of the body; closed by this sieve on the outside, all the water that passes into it is purified from all foreign substances that might be injurious to the animal, and is thus fitted to pass into the water-system, from which arise the main branches leading to the minute suckers which project through the holes in the narrow zones of plates.



Now in order to transform theoretically our Sea-Urchin into a Star-Fish, what have we to do? Let the reader imagine for a moment that the small ab-oral area closing the space between the ovarian plates and the eye-plates is elastic and may be stretched out indefinitely; then split the five broad zones along the centre and draw them down to the same level with the mouth, carrying the ovarian plates between them. We have then a star, just as, dividing, for instance, the peel of an orange into five compartments, leaving them, of course, united at the base, then stripping it off and spreading it out flat, we should have a five-rayed star.



But in thus dividing the broad zones of the Sea-Urchins, we leave the narrow zones in their original relation to them, except that every narrow zone, instead of being placed between two broad zones, has now one-half of each of the zones with which it alternated in the Sea-Urchin on either side of it and lies between them. The adjoining wood-cut represents a single ray of a Star-Fish, drawn from what we call its lower side or the oral side. Along the centre of every such ray, diverging from the central opening or the mouth, we have a furrow, corresponding exactly to the narrower zones of the Sea-Urchin. It is composed of comparatively small perforated plates through which pass the suckers or locomotive appendages. On either side of the furrows are other plates corresponding to the plates of the broad zones in the Sea-Urchin. Where shall we look for the five eyes? Of course, at the tip of every ray; exactly where they were when the rays were drawn up to form the summit of a sphere, so that the eyes, which are now at their extremities, were clustered together at their point of meeting. Where shall we look for the ovarian plates? At each angle of the five rays, because, when the broad zones of which they formed the summit were divided, they followed the split, and now occupy the place which, though it seems so different on the surface of the Star-Fish, is nevertheless, relatively to the rest of the body, the same as they occupied in the Sea-Urchin. Assuming, as we premised, that the central area of the ab-oral region, forming the space between the plates at the summit of the zones in the Sea-Urchin, is elastic, it has stretched with the spreading out of the zones, following the indentation between the rays, and now forms the whole upper surface of the body. All the internal organs of the animal lie between the oral and ab-oral regions, just as they did in the Sea-Urchin, only that in the Star- Fish these regions are coequal in extent, while in the Sea-Urchin the ab-oral region is very contracted, and the oral region with the parts belonging to it occupies the greater part of its surface.

Such being the identity of parts between a Star-Fish and a Sea-Urchin, let us see now how the Star-Fish may be transformed into the Pedunculated Crinoid, the earliest representative of its Class, or into a Comatula, one of the free animals that represent the Crinoids in our day.



We have seen that in the Sea-Urchins the ab-oral region is very contracted, the oral region and the parts radiating from it and forming the sides being the predominant features in the structure; and we shall find, as we proceed in our comparison, that the different proportion of these three parts, the oral and ab-oral regions and the sides, determines the different outlines of the various Orders in this Class. In the Sea-Urchin the oral region and the sides are predominant, while the ab-oral region is very small. In the Star-Fish, the oral and ab-oral regions are brought into equal relations, neither preponderating over the other, and the sides are compressed, so that, seen in profile, the outline of the Star-Fish is that of a slightly convex disk, instead of a sphere, as in the Sea-Urchin. But when we come to the Crinoids, we find that the great preponderance of the ab-oral region determines all that peculiarity of form that distinguishes them from the other Echinoderms, while the oral region is comparatively insignificant. The ab-oral region in the Crinoid rises to form a sort of cup-like or calyx-like projection. The plates forming it, which in the Star-Fish or the Sea-Urchin are movable, are soldered together so as to be perfectly immovable in the Crinoid. Let this seeming calyx be now prolonged into a stem, and we see at once how striking is the resemblance to a flower; turn it downwards, an attitude which is natural to these Crinoids, and the likeness to a drooping lily is still more remarkable The oral region, with the radiating ambulacra, is now limited to the small flat area opposite the juncture of the stem with the calyx; and whether it stretches out to form long arms, or is more compact, so as to close the calyx like a cup, it seems in either case to form a flower-like crown. In these groups of Echinoderms the interambulacral plates are absent; there are no rows of plates of a different kind alternating with the ambulacral ones, as in the Sea-Urchins and the Star-Fishes, but the ab-oral region closes immediately upon the ambulacra.

It seems a contradiction to say, that, though these Crinoids were the only representatives of their Class in the early geological ages, while it includes five Orders at the present time, Echinoderms were as numerous and various then as now. But, paradoxical as it may seem, this is nevertheless true, not only for this Class, but for many others in the Animal Kingdom. The same numerical proportions, the same richness and vividness of conception were manifested in the early creation as now; and though many of the groups were wanting that are most prominent in modern geological periods, those that existed were expressed in such endless variety that the Animal Kingdom seems to have been as full then as it is to-day. The Class of the Echinoderms is one of the most remarkable instances of this. In the Silurian period, the Crinoids stood alone; there were neither Ophiurans, Asteroids, Echinoids, nor Holothurians; and yet in one single locality, Lockport, in the State of New York, over an area of not more than a few square miles, where the Silurian deposits have been carefully examined, there have been found more different Species of Echinoderms than are living now along our whole Atlantic coast from Maine to Florida.

There is nothing more striking in these early populations of the earth than the richness of the types. It would seem as if, before the world was prepared for the manifold existences that find their home here now, when organic life was limited by the absence of many of the present physical conditions, the whole wealth of the Creative Thought lavished itself upon the forms already introduced upon the globe. After thirty years' study of the fossil Crinoids, I am every day astonished by some new evidence of the ingenuity, the invention, the skill, if I may so speak, shown in varying this single pattern of animal life. When one has become, by long study of Nature, in some sense intimate with the animal creation, it is impossible not to recognize in it the immediate action of thought, and even to specialize the intellectual faculties it reveals. It speaks of an infinite power of combination and analysis, of reminiscence and prophecy, of that which has been in eternal harmony with that which is to be; and while we stand in reverence before the grandeur of the Creative Conception as a whole, there breaks from it such lightness of fancy, such richness of invention, such variety and vividness of color, nay, even the ripple of mirthfulness,—for Nature has its humorous side also,—that we lose our grasp of its completeness in wonder at its details, and our sense of its unity is clouded by its marvellous fertility. There may seem to be an irreverence in thus characterizing the Creative Thought by epithets which we derive from the exercise of our own mental faculties; but it is nevertheless true, that, the nearer we come to Nature, the more does it seem to us that all our intellectual endowments are merely the echo of the Almighty Mind, and that the eternal archetypes of all manifestations of thought in man are found in the Creation of which he is the crowning work.

In no group of the Animal Kingdom is the fertility of invention more striking than in the Crinoids. They seem like the productions of one who handles his work with an infinite ease and delight, taking pleasure in presenting the same thought under a thousand different aspects. Some new cut of the plates, some slight change in their relative position is constantly varying their outlines, from a close cup to an open crown, from the long pear-shaped oval of the calyx in some to its circular or square or pentagonal form in others. An angle that is simple in one projects by a fold of the surface and becomes a fluted column in another; a plate that was smooth but now has here a symmetrical figure upon it drawn in beaded lines; the stem which is perfectly unbroken in one, except by the transverse divisions common to them all, in the next puts out feathery plumes at every such transverse break. In some the plates of the stem are all rigid and firmly soldered together; in others they are articulated upon each other in such a manner as to give it the greatest flexibility, and allow the seeming flower to wave and bend upon its stalk. It would require an endless number of illustrations to give even a faint idea of the variety of these fossil Crinoids. There is no change that the fancy can suggest within the limits of the same structure that does not find expression among them. Since I have become intimate with their wonderful complications, I have sometimes amused myself with anticipating some new variation of the theme, by the introduction of some undescribed structural complication, and then seeking for it among the specimens at my command, and I have never failed to find it in one or other of these ever-changing forms.

The modern Crinoid without stem, or the Comatula, though agreeing with the ancient in all the essential elements of structure, differs from it in some specific features. It drops its stem when full-grown, though the ab-oral region still remains the predominant part of the body and retains its cup-like or calyx-like form. The Comatulae are not abundant, and though represented by a number of Species, yet the type as it exists at present is meagre in comparison to its richness in former times. Indeed, this group of Echinoderms, which in the earliest periods was the exponent of all its kind, has dwindled gradually, in proportion as other representatives of the Class have come in, and there exists only one species now, the Pentacrinus of the West Indies, which retains its stem in its adult condition. It is a singular fact, to which I have before alluded, and which would seem to have especial reference to the maintenance of the same numeric proportions in all times, that, while a Class is represented by few types, those types are wonderfully rich and varied, but in proportion as other expressions of the same structure are introduced, the first dwindle, and, if they do not entirely disappear, become at least much less prominent than before.