but a mushroom still vaster and more vigorous than the oak?* Not but the one as well as the other, at what time soever planted, must equally have been planted by projectors; for though Tubal Cain himself were to be brought post from Armenia to plant Sheffield, Tubal Cain himself was as arrant a projector in his day as even Sir Thomas Lombe was, or Bishop Blaise. The earnestness with which he returned to the subject in his "Manual of Political Economy," shows the value which he attached to it. Abstract science, until within a comparatively recent period, was the almost exclusive occupation of all men claiming to rank among the "sect of the philosophers." With the brilliant personal exception of Watt, they appear to have considered it beneath their dignity to carry out their learned theories into any practical or profitable employment. Great mechanical ingenuity they no doubt displayed; but it was devoted to the construction of instruments adapted to scientific research, some of which, it is true, have since been found of util As the world advances, the snares, the traps, the ity to the general public. A few investigations pitfalls, which inexperience has found in the path were diligently prosecuted which promised to be of inventive industry, will be filled up by the for- of national benefit, such as those relating to the tunes and the minds of those who have fallen into longitude, chronometers, and the lunar theory; them and been ruined. In this, as in every other but they were entertained rather as favorite sciencareer, the ages gone by have been the forlorn tific puzzles, inherited from past generations, than hope, which has received for those who followed as problems whose solution would prove a vast them the blows of fortune. There is not one reason for hoping less well of future projects than commercial good. Davy's safety lamp was alof those which are passed, but here is one for hop-most an exception, at the time it appeared; and ing better. Nothing would more contribute to the people wondered to hear that Herschel had made preliminary separation of useless from useful proj- anything in the vulgar way of money by his teleects, and to secure the laborers in the hazardous scopes, or Wollaston by his platinum. "Their routes of invention from failure, than a good treatise bays are sere, their former laurels fade," is the upon projects in general. It would form a suitable sentence pronounced by Byron upon the poets— appendix to the judicious and philosophical work of the Abbé Condillac upon systems. What this is but it was recorded also at that period against all in matters of theory, the other would be in matters laborers in the field of intellect—who might "deof practice. The execution of such a work might scend to trade." Byron can have little thought be promoted by the proposal of a liberal reward for that it should appear in the posthumous edition of the most instructive work of this kind. his works, that he lived to receive for copyright from Mr. Murray £23,540. per A survey might be made of the different branches of human knowledge; and what each presents as The tendencies of the present age are, perhaps, most remarkable in this respect might be brought to view. Chemistry has its philosopher's stone; too much the reverse of this; and have become medicine its universal panacea; mechanics its too exclusively practical. In science, as in polipetual motion politics, and particularly that part tics, it may be an empty pedantry to recur too which regards finance, its method of liquidating, constantly to first principles; but it is worse than without funds and without injustice, national debts. pedantry to attempt to do without them. Yet this Under each head of error, the insuperable obstacles attempt is made every day by persons who will presented by the nature of things to the success of not undertake, or cannot appreciate, the incessant of any such scheme, and the illusions, which may labor by which the pioneer of discovery must conoperate upon the human mind to hide the obstacles, solidate his progress. When men of science or to nourish the expectation of seeing them surmounted, might be pointed out. Above all, dis- hardly dare to assert their comprehension of the honest projectors, impostors of every kind, ought to elementary principles of some novel theory, the inbe depicted; the qualities of mind and character, ventor rushes in with his prospectus and patent, to which they possess in common, should be described. turn it to account. As a matter of course, failure But throughout the whole work, that tone of malig- and loss are the result; and science itself will nity which seems to triumph in the disgraces of genius, and which seeks to envelope wise, useful, sometimes share the inevitable discredit, or the and successful projects in the contempt and ridicule calm philosopher may be turned away from the inwith which useless and rash projects are justly vestigation, which only he can follow duly, by the covered, should be guarded against. Such is the atmosphere of fallacy-or, to use a plain word, character, for example, of the works of the splenetic humbug-that has been thrown around it. Before Swift. Under the pretence of ridiculing projectors, the very alphabet of the electro-magnetic action he seeks to deliver up to the contempt of the ignowas accurately understood, contrivances were rant, the sciences themselves. They were hateful in his eyes on two accounts; the one, because he busily placarded whereby its agency was to superwas unacquainted with them; the other, because sede the steam engine. Whatever truth there they were the work, and the glorious work, of that may be in the facts of phrenology or the theories race which he hated ever since he had lost the hope of mesmerism, has been fatally obscured through of governing part of it. the eager determination of empirics to "work the idea" profitably. Those who have been disgusted with the puff, or pillaged by the charlatan, are not unlikely to pass upon the whole subject a hasty sentence of transportation beyond the pale of philosophical inquiry. *The present state of Sheffield is a painful answer to Bentham's question. We read (Dec. 1848) in the Shef field Times," What is to become of Sheffield? The introduction of a new trade alone will save us." + First edited from Bentham's MS. in the third volume of his works, printed at Edinburgh, 1843. The "curiosities of the patent rolls" would Inventions of grander aim are of course almost furnish materials for a copious chapter in some innumerable. Some are vaguely described as work devoted to an exhibition of the eccentricities" new modes of obtaining motive power;" others of intellect. Even the titles affixed as labels to a as rotary, locomotive or marine engines. A large multitude of inventions suggest very curious reflec- number refer to our staple manufactures; as, tions. In the list of patents registered during a "machines for spinning and weaving," or for few months of 1846 and '47, given in the works" preparing, slubbing, and roving cotton and other mentioned at the head of this article, we find, fibrous substances." We find one invention for along with a numerous family of contrivances for "aerial locomotion ;" and several for "making personal and household uses, one for an "anti-roads and ways." emergent rat-trap;" others for " improvements in For the agriculturist there are machines for bedsteads," in pianofortes, saddles, and penhold-"cutting, slicing, or otherwise dividing, hay, ers; for 66 a new fastening for shutters;" for se- straw, or turnips;" several improvements in "tillcuring corks in bottles; and for "certain improve- ing land;" and one of very comprehensive characments in the manufacture of spoons." Articles of ter, for "certain carbonic compounds, formed of dress supply their quota. We have improvements earth, vegetable, animal, and mineral rubbish, in "sewing and stitching ;" a new mode of apply- fecal substances, and waste of manufactories, and ing springs to braces;" improvements in "hats, certain acids and alkalies, which compounds are caps, and bonnets;" an "improved apparatus to applicable as manures.' be attached to boots and shoes in order to protect the wearer from splashes of mud in walking ;" and a long list of inventions connected with the application of gutta percha. 66 A few inventions are of American origin, and sufficiently characteristic. One is for improvements in finishing raw hide whips; one or two more for the manufacture of cigars; but the most The military and naval professions appear curious of all is described as the "Patent Enuncirather out of fashion. Nevertheless, an improve- ator; being a substitute for the usual suit of bells ment is registered "in the manufacture of bay- in hotels." It consists of a highly ornamental onets;" and another for "warping and hauling rosewood frame, on which two hundred numbers vessels," the inventor being designated Commander are conspicuously arranged, each ordinarily marked R. N. For the literary profession an improved by a sector card delicately hung on a pivot conink has been invented by "M. J. B. Reade, nected with the machinery. When any one of clerk ;" and a Birmingham merchant registers the two hundred pulls is started, a hammer strikes some new and improved instruments or machines on a delicately toned bell-and the figures of the for effecting or facilitating certain arithmetical corresponding number are unmasked, the vibration computations or processes.' The medical pro- of the card continuing for some seconds to indicate fession is enriched by a "new apparatus for the the numbers last brought into view. The inventor, treatment of distortions of the spine;" improve- a Mr. Johnson of New York, was stated to have ments in "artificial palates;" in the manufacture on hand more orders than he could supply. of epithems; "the cutting of lozenges;" and “a means or apparatus for administering certain matters to the lungs for medical or surgical purposes;" by which vague description it was intended to specify the instruments used in the inhalation of ether. 66 The arts follow naturally the professions; and we observe that the peculiar branch of art which owes so much to the genius of M. Soyer holds a deserved rank in the estimation of inventors. They have furnished us with improvements in "the mode of making comfits," of "preserving fruit and vegetables," of "storing beer, ale and porter;" with a new apparatus for hatching eggs ;" and a "collapsible tube for sauces, made by placing a solid piece of tin upon a properly shaped matrix, when a rod of steel being forcibly impressed thereon a thin tube is formed. The sauces are enclosed in the tube and expelled by squeezing, so there is no waste or leakage and no air admitted to corrupt the purity of goût." This, invention, however ridiculous it may sound, has been found useful in other arts besides cooking; and has been adopted as a reservoir of colors for painters, and generally when it is required that substances should be preserved in a moist state and secured from atmospheric influence. It is a theory rather in favor with inventors, that many of the most brilliant discoveries have been made by accident; and indeed the examples are sufficiently well known, of apparently fortuitous occurrences giving birth to very wonderful realities. But if we could inquire more accurately, we should probably learn that the lucky accident had but set in motion a certain train of thought in an already prepared mind; while by far the majority of cases exhibit to us the new discovery elaborated by reiterated trials and improvements from its rude original. A word dropped in casual conversation suggested an idea to the mind of a clergyman (Cartwright) of practical and benevolent tendencies; which, under the influence of contradiction, became hot and strong enough to absorb all his energies for the production of a power loom. On the other hand, we hear of a practical manufacturer (Radcliffe) becoming convinced that it was possible and desirable to effect a certain operation by machinery instead of manual labor; and shutting himself up with workmen and tools for many months, until he emerged from his seclusion with a warp-dressing machine, to testify to the success of their prolonged exertions. Even the simplest-looking contrivances require knowledge, especially mathematical knowledge, of Hogarth said that he would allow all the world to be judges of his paintings, except members of his own profession: and, in general, scientific men would submit their ideas to the approval of all, with the exception of men of their own pursuits. No man is a prophet in his own country, and men of science are too often the least qualified to form an estimate of an invention in their own branch of knowledge. To submit a novelty for the approval of men accustomed to the routine and forms in present use, is oftentimes to ensure its rejection. no ordinary degree at every step. The mere cal- | upon this point only the prevailing sense of the culation, for example, of the best form to be given public when he observes:to the teeth of wheels, which are intended to transmit motion reciprocally, requires a process of analysis beyond the competence of ninety-nine in the hundred even of educated men. In more primitive stages of the mechanical arts great nicety was not required. The cogs were then rudely notched in the peripheries of the wooden wheels by the saw or chisel. But now that more perfect workmanship is necessary, the mechanist must form the surfaces of the teeth into such a curve that they shall roll instead of rubbing on one another, as they successively come in contact, and the friction and wear of material be thus reduced to a minimum. It is true that many of these calculations are already prepared and published in tabulated forms, and therefore the inventor is not called upon to calculate them for himself. But few can hope to become successful improvers, who are not at least competent to understand their nature, and able to determine the particular points of every new contrivance where such considerations become impor tant. The writer then proceeds, according to the invariable rule, to invoke the overworked shades of Harvey and Galileo as illustrations of his statement. A more popular suggestion has been made, that every patentee should be required to deposit in some public museum an accurate model or specimen of his invention; which would thus prove highly useful as an object of interest and instruction to others, as well as by rendering more easy of determination any litigated question of priority. We should anticipate this further advantage from the plan the attempt to construct his model would often leave the inventor self-convicted of the inutility of his scheme and save him much disap drawing often has a salutary effect. Mr. Babbage relates that in the construction of his calculating machine, not one single portion of the works, although these were of extraordinary complication, required any alteration after it was once made, owing to the admirable care which had been bestowed upon the drawings. But we fear that what is called the inventive faculty is a quality far more cheap and abundant, than the patience that can trace, or the understand-pointment. Even the preparation of an accurate ing that can comprehend, the delicate theorems which ought to guide the inventor, and can alone shield him from failure. Ambition too perpetually misleads him, and beguiles him into attempting the grandest achievements of science, with insufficient means and imperfect knowledge. Artists who could command a decent livelihood as sign-painters, still heroically starve amid their unsaleable canvass daubed with pictures of the historic order! Johnson has immortalized the folly of a man who announced himself to the occupants of an inn parlor, as the Great Twalmley, inventor of the new Floodgate Iron. But so innocent a vanity hardly deserved to be treated with so much contempt. Mr. Twalmley had, at all events, obtained success and fortune, to justify his self-conceit. Ridicule would far more justly be bestowed upon those half-informed mechanicians, who aspire to change the whole aspect of our national industry or our system of warfare, by the application of abilities which, at best, might be usefully devoted to domestic purposes, or the invention of instruments ranking with the Floodgate Iron. Were it not that no exercise of tyranny would be more fiercely resented than any attempt to interfere with the true-born Englishman's privilege to throw away his time and money at his own pleasure, we could suggest the appointment of certain boards of examiners, whose approval should be first secured before any invention, purporting to be novel, could be admitted to the expensive honors of a patent. We well know, however, how distasteful the suggestion would prove, and how jealously an inventor would regard the opinion of any men competent to judge of the matter referred to them. A writer in the Patent Journal expresses Το It is not, however, solely with the view of saving a few inventors the pain of disappointment, that we would have the conditions and limits of practical attainment accurately traced out. Still less is it in the spirit of the ancient geographers, who drew the lines that marked the boundaries of their known world upon their maps, and then wrote "nil ultra" outside them. For to us, who have learnt that the universe is inexhaustible, the time will never come when we shall believe, of any field of research, that there is nothing more to be discovered in it. But we conceive that to ascertain the precise nature and place of the obstacles which at present retard our advance, is the surest preliminary to any attempt at their removal. know where the barrier lies, will instruct us also where lie the domains of richest promise, not yet rifled by discoverers. To know what it is, will guide us to the selection of those aids and appliances by which it is to be broken or overleapt. Dr. Hooke has remarked, that whenever in his researches he found himself stopped by an apparently insurmountable difficulty, he was sure to be on the brink of a valuable discovery. In his day the world was so little explored, that its richest prizes might still be stumbled upon by mere chance. The philosopher upon his voyage of discovery, like Genseric upon his voyages of conquest, might abandon the helm and let his bark pose. where we find that nature herself raises the barrier in our path. Man has succeeded in rendering almost every quality of every various form of material substance available for some purpose of utility. On certain occasions only, and for certain purposes, some one or other of those qualities will be found to stand in the way of his success. sail "whithersoever the winds might carry her;" the mechanism necessarily employed. The higher trusting that fortune would lead him within sight importance of the former class is at once manifest. of some region wealthy and unknown, of which | Difficulties which arise from construction may be he could claim possession by the prior right of oc- overcome or eluded; but the task is very different cupancy. But such happy casualties are now barely possible; the harvest has been too well gleaned for mere adventurers. Within the limits of the nearer horizon, science has left, in the words of the old feudal law, "Nulle terre sans seigneur ;"—but it must not be forgotten that she has at the same time afforded aid and means to furnish us forth for more distant enterprises. And Chemistry has gone far towards establishing we are enabled also to save ourselves the trouble the hypothesis that all natural bodies are susceptiof many a profitless voyage; for we have, by her ble of assuming three forms-the solid, fluid, and help, in several instances accomplished that most gaseous-according to the degree of HEAT by difficult task, whether in law or physics, of prov- which they are affected. At all events it is cering a negative. We may feel sure that nothing tain that heat exercises, in various proportions, more is to be done at least in certain directions such an influence on the constituent atoms as to -with our present means and instruments; as destroy or diminish their mutual attraction; and their range has been already ascertained and their even when the mass does not subside into fluidity, powers tasked to the uttermost. On another side, it loses its strength and cohesive properties, and we can determine, without the necessity for costly becomes disintegrated. The uses to which this experiments, and indeed often, by the application property of matter has been applied are infinite. of theory alone, which of two or more possible Let us see how it may become a limitary princiarrangements of mechanism will prove most effica-ple. cious for the accomplishment of the desired pur- It is supposed that the possible heat of a burning atom (in which of course we shall find the In fact, the votary of science is now able to theoretical limit) is very far above the highest proceed towards discovery with sure and certain known temperature attained in our furnaces; and steps. He knows whither he is going; and he it would consequently follow that we might more allows nothing to escape him unnoticed on the nearly approach that limit by varying the arrangeroad. Every new phenomenon, as it comes with- ment of the fuel and the supply of air for comin his ken, is duly compared with his previous ex-bustion. This has been accordingly done, until perience, and it is not admitted to assume its title we have found our progress stopped by the imposuntil it has been examined and tested with the sibility of discovering any substance, whereof to most minute accuracy. In the same manner, ev- build our furnaces, which will bear the heat. ery deduction to which he arrives is scrutinized Porcelain, firebrick, and plumbago, in various with jealous care, and not until it has undergone combinations, are adopted; but they either crumevery trial that ingenuity can devise, is it permit-ble, or sink down into a pasty mass, as the fire ted to take rank among the links destined to com- is urged. The qualities of matter itself here act pose the great chain of his theory. The end of as a complete "estoppel ;" and if we would exall his researches is indeed always kept in sight;perimentalize further upon the phenomena of calbut he never jumps at a conclusion; nor suffers oric, we can operate only upon a minute scale by his impatience for a result to hurry him into a means of the gas blowpipe, or the heated arch neglect of those precautions which can alone se- evolved from charcoal points interposed in a galcure for that result the certainty and precision on vanic circuit. But for this limit, many useful purwhich its value depends. By no meteor of the poses might be accomplished, by the mutual actions marsh must the traveller be guided, who would or changed forms of material bodies when subpenetrate the trackless expanses of the Unknown!jected to the intense action of heat. For instance, The subject we have here traced out is far too in the case of platinum-we might then separate extensive for us to attempt, within our allotted it from its ores by the ordinary methods of smeltlimits, to fill up its outline at every point. We ing and fusion; in place of being compelled to can but endeavor to indicate, by a few precepts adopt the laborious and costly process of solution and examples, the peculiar nature of the problems in acids. The steam-engine offers an example which every inventor will have to work out for nearly parallel. The power of a steam engine dehimself, whenever he wishes to determine the lim-pends primarily upon the area of surface in the its between the possible and the impossible. boiler exposed to the action of the fire, and the The limitary principles (by which term we pur-intensity of the fire itself. In marine and locomopose to specify everything, whether quality or accident, which tends to limit our progress towards perfection) may be divided into two great categories-including, first, those derived from the natural properties of matter; and, secondly, those arising from the construction or arrangement of tive engines, where space must be economized, the practical limit is fixed only by the degree of heat; and this of course must be kept below the utmost limit which the material of the boiler furnace will endure. As yet, there has not been discovered any material better fitted for this purpose than iron; and we have made our fires as fierce as the| melting point of iron will permit; even now, the firebars are destroyed sometimes upon their first journey. WEIGHT is one of the properties of matter which in practice we encounter chiefly as an obstacle or inconvenience, tending to increase friction, to resist motion, and generally to crush and destroy. Meanwhile, the limits of its range are comparatively narrow-that is to say, on one side. We can, indeed, rarify a gas until its weight disappears in infinite tenuity; but we very soon find ourselves at the extreme verge of any possible increase of specific gravity. The most ponderous substance known is not quite 22 times heavier than water. And yet there are many purposes for which bodies of greater weight might be made useful. If, for example, closer or deeper search amid the stores of the mineral kingdom should lead to the discovery of some substance bearing the same proportionate gravity to platinum that platinum does to cork, how many possibilities of improvement would be placed within our power! A thin sheet of such a substance, interposed among the keel timbers of a ship, would give stability and other sailing qualities at present unattainable. Blocks of it would afford sure foundations for piers, bridges, and all marine works. It might then be found no longer impossible to establish a lighthouse on the Goodwins. As a regulator, or reservoir, of power-for counterpoises, pendulums, and fly-wheels; for all purposes where percussive force is required; and in steam hammers, piledrivers, and shot of long range, the utility of such a substance would be enormous. In each and all of these objects we are limited by the limits of spécific gravity in our materials. Further than this we obviously cannot go, so long as we use water for the power-producing agent. Attempts have however been made to conquer the difficulty by taking advantage of some other properties of matter in its relation to heat; based upon the fact that the "evaporating point" that is, the degree of heat at which fluids expand into vapor-is found to differ considerably in different liquids, just as does the melting point of solid bodies. It would, therefore, appear probable that by filling the boiler with alcohol, which boils at 173°, or with ether boiling at 96° Fahrenheit, the tension of the vapor and consequent power of the engine could be increased without increasing the heat of the furnace. As both of the abovementioned fluids are expensive, it was first requisite so to contrive the machine that no loss should be experienced, but the whole vapor be recondensed and returned to the boiler. For this purpose a variety of ingenious contrivances have been suggested, the earliest of which, and one perhaps as effectual as any other, was patented by Dr. Cartwright in 1797; while new forms of mechanism, with the same object in view, are even still appearing on the patent rolls from time to time. Whatever the ingenuity of man could do, has probably, therefore, been done; but the practical utility of all these contrivances was destroyed by the influence of other properties of matter altogether overlooked, although of necessity involved in the question. These regard the relative bulk of the vapor produced from corresponding quantities of different fluids, and the proportion of heat absorbed or rendered latent in each during the process of vaporization. The calculation is sufficiently simple; and the result effectually annihilates all hope of advantage, either potential or economical, from the ethereal or alcoholic engines. Thus, to convert a given weight of water into steam, 997 degrees of heat are required as what is called "caloric of vaporization." The same quantity of alcohol will become vapor with 442 degrees, and sulphuric ether with only 302°. But to set against this apparent gain, we find that the specific gravity of steam (air being =1) is 6235; vapor of alcohol 1.603; ether 2·586; and the re-apparatus consists of a series of vanes with attached sult may be thus tabulated. Caloric of Spec. Grav. Water, Alcohol, 997° Sulph. Ether, 302° 6235 1.603 2.586 Useful effects By an incidental quality, in some measure associated with the specific gravity of bodies, we find that while all substances, without exception, undergo condensation when subjected to pressure, they do not all resume their original condition when the pressure is withdrawn. As might be supposed, the lighter bodies exhibit this peculiarity in the highest degree. Wood, for example, after having been submerged in the sea to a depth of two or three thousand feet, is found to be no longer light enough to float; the hydrostatic pressure, exceeding half a ton on every square inch, having both compressed the fibrous mass and injected the pores with water. By this peculiarity, the usefulness of an otherwise admirable instrumentthe Sounding Machine-is much restricted. Its clockwork, to denote the depth of water through which it has sunk. A buoy or float is fixed on the upper part, and the machine being loaded with 10,000 a sufficient weight descends until it strikes the 8,776 ground; on this, the weight becomes detached 7,960 and the instrument returns to the surface, bringing The disadvantage of the lafter fluids will be further back a faithful record of the perpendicular disenhanced by the circumstance that, being lighter than water, a larger boiler will be required to hold the same weight of vaporific fluid: i. e., a pound of water, when evaporated, will form about 21 cubic feet of steam; while a pound of ether will require a larger boiler to hold it, and will only form 5 cubic feet. tance traversed. For ordinary depths the float consists of a hollow copper sphere; but as the metal must necessarily be thin it is crushed in by a comparatively slight pressure. A wooden float is therefore substituted, which is able to command a more extended range of soundings, until the limit is reached at which the pressure already spoken of |