A writer in the New York Tribune has given expression to singular views in regard to the character of American inventors. He says that “ with some notable exceptions, they have exhibited their powers of invention with reference to secondary rather to general principles ; more by using the discoveries of other people than their own.” “Ofcourse,” he continues, “we shall be told that there are hut few general principles, while the details may be considered as infinite, and we shall be reminded, too, that upon Dr. Franklin's discoveries in electricity almost a whole science has been founded— that steamboat navigation, the use of ether in surgery, the mowing machine, are ours, and the power-printing press, the telegraph, and the sewing machine, were all conceived beneath the skies of this new world. We grant that these, and others which could be named, are proud achievements, and their application to so many of the wants of daily life gives them especial prominence ; still, we ought to consider that, in compass, acuteness, and perseverance, the English mind is unexcelled, for to it we owe the discover' of the use of steam, the invention of the steam engine, of the power loom, of the spinning jenny, and of the locomotive and railway, all of which required the application of grand principles, and they are of such immense utility that they have an influence upon almost every being on the face of the globe. However, the art of printing from movable types clearly was a necessary preliminary, and it would seem that the German nation was not to be deprived of Borne share in the great work of modern progress." The writer of this paragraph has evidently not comprehended the distinction between invention and discovery. Invention is the application of general principles. to the construction of new machinery or the development of new processes. Discovery has nothing in common with it. The former either discards experiment, or uses it only to verify the truth of previous conceptions arrived at by a process of pure reasoning. The latter progresses only through theory only pointing out probable paths of discovery in which to conduct experimental research. The inventions alluded to by this writer were all, in this © 1869 SCIENTIFIC AMERICAN, INC. 250 Jricwtific American. [October 16, 1869. regard, secondary, orbased upon general principles previously discovered. While \ve grant to England a large share of honor, both for discovery and invention, we not oiily accord to Germany and France equal shares of honor in the development of general principles, upon which England and America have based their inventions, but we unhesitatingly assert that, when the age of these nations is taken into account, America has led them all, both in discovery and invention. The length of this article will forbid entering upon a,n argument to prove the truth of this claim, but we shall not hesitate to take up the gauntlet in its defense at a future time should it meet with denial. Ample illustration of the originality and comprehensive character of American inventive genius may be found in the MACHINERY DEPARTMENT of the American Institute Exhibition, to which, after two weeks' enforced delay, we now invite the attention of our readers. Much of the delay was caused by the tardiness of exhibitors, and also to the fact that the unexpected magnitude of the display in this department took the managers by surprise. Preparations to transfer a portion of the machinery to the main floor were necessitated ; the structure specially erected for this purpose proving too small to place all who desired room. This compelled extension and modification of the original plan, the erection of new lines vf shafting, etc.; but at last all these obstacles are surmounted, and every machine, we believe, which demanded power has been or will be accommodated. THE BOILERS which supply the main driving engines with steam are three, known as the Root, the Harrison, and Salisbury boilers. The former is made and exhibited by the Root Steam Engine Co. of New York. It was illustrated and described on page 373, Vol. XX., of the Scientific American, to which the reader is referred. The Harrison boiler is of peculiar construction, being composed of hollow cast-iron globes or shells communicating with each other in all directions, by short tubes, so as to permit of a free circulation, around and between these globes and tubes the heated gases of combustion play. Immense heating surface is secured in this way, while each of the globes may be considered as a separate small boiler, having only the same liability to explode that would attend an isolated boiler of the same size and construction. There can be no doubt that these boilers will endure, with safety, enormous pressures, and their steam-generating' power is said to be highly satisfactory. This boiler is made and exhibited by Joseph Harrison, of the Harrison Boiler Works, Philadelphia. The Harrison boiler has attached to it Berryman's Patent LOW-WATER ALARM, constructed on a novel principle, and evidently a very sensitive instrument. It consists of a globe and steelyard, with counterpoise. When the water is at the proper hight the globe stands full of water, and its weight counterbalances the weight on the steelyard. As soon as the water falls too low, Pteam immediately replaces the water in the globe, and the counterpoise falls a short distance, opening a whistle valve, which gives an alarm. The same instrument might easily be adapted to control the feeding of a boiler by means that will readily suggest themselves to engineers. The Salisbury boiler is a new claimant for public favor, and we hear it spoken well of. We are, however, unable to give details of its construction. At the present writing it had not yet been used to supply steam to any of the engines, though wewere informed that Rider's engine mentioned below would be driven by it. These boilers are placed outside the main building under an open shed, the managers not permitting any fires on the floor of the building in which the exhibition is held. In this shed are also placed some of the engines exhibited, which we will notice in passing. Adjacent to the Root boiler stands the Roper IMPROVED CALORIC ENGINE, Illustrated and described on page 257, Vol. XX., of this journal, to which we refer the reader. We have no doubt that this engine deserves to rank among the best of its class now in market, and as a small, portable, safe motor, it may be advantageously applied where steam is out of the ques-. tion. Here stands, also, the portable engine invented by William Baxter, of Newark, N. J., illustrated and described on page 353, Vol. XX., of this journal It is quite evident from the interest taken in this engine by engineering visitors to the Fair, and the warm encomiums bestowed upon it, that this engine is to occupy a prominent place among improvements of a similar character in this country. The engine is placed disadvantageously on account of the conditions of the lease above specified, but notwithstanding this drawback it will make its mark. It consumes the smoke so thoroughly, and employs such a small quantity of steam, that notwithstanding the exhaust enters the smoke-pipe, no sign of either smoke or steam can be seen issuing from the end of the smoke-pipe. It is driving two blowers, requiring four-horse power, as tested by Neer's dynamometer, and does this work with a surprising economy of fuel. These blowers will be more particularly noticed in a subsequent article, together with others on exhibition. On the MAIN FLOOR of this department are placed a number of large horizontal engines, which are well finished, and the peculiarities of which are well known to engineers. we shall not, therefore, in our notice of these, enter much into details, but confine ourselves to such general remarks as suggested themselves to us in the brief time we could allot to each of them. The designs of these steam engines show much taste and skill, and most of them are highly ornamented in their finish. The Fishkill Landing Machine Works exhibit a thirty-horse horizontal engine having tapering, cylindrical, and, consequently, balanced valves, so adjusted that their wear can be taken up by a set screw. The ports in these valves are formed analogously to those of the gridiron slide valve. The movement of the valves is obtained by a system of plain and bevel gearing, the induction valves being actuated by a differential cam, which, through the action of the governor, gives the required cut-off. The exhaust valves are worked by a simple eccentric, driven by the same gearing which imparts motion to the differential cam.. The Novelty Iron Works horizontal engine, illustrated and described on page 161, current volume, of the Scientific American, will be exhibited although not yet in place. A stationary engine of eighty-horse power made and exhibited by Babcock&Wilcox, of New York, is a good engine. The motions of the valves are shown through glass plates. The peculiar features of this engine were fully described and illustrated on page 257, Vol. XVII., of this journal, to which we refer the reader. The cut-off valves are actuated by the steam itself. The governor is of peculiar construction, by which all variation, consequent upon the movement of the balls in an arc of a circle, is obviated, these balls having a parallel motion instead of the ordinary one. The valves also have a constant travel under all circumstances by which many advantages are secured. Altogether this engine will repay careful examination from engineers visiting the department. The Delamater Engine Co., of New York, exhibit a very handsomely designed horizontal engine of the Rider's Patent, and also an upright engine constructed on the same general principle. In this engine the cutoff valve ports are cut obliquely to the longitudinal axis of the main valve, on the back of which plays the cut-off valve. The cut-off valve face is convex, and the seat is turned out to the true arc of a circle. The form of the valve is triangular in plan, and the two oblique parts in the seat are placed relatively at the same angle as the corresponding sides of the valve. A partial rotation of this valve on its spindle, therefore, opens or covers these ports sooner or later in the stroke, and the motion which performs this partial rotation is derived from the governor. The cut-off may be made, therefore, at any point of the stroke desired, the parts employed to accomplish these results being very few and simple. William A. Harris, of Providence, R. 1., exhibits one of the celebrated Corliss engines of eighty-horse power. It would be entirely superfluous to dwell upon the construction of this engine, which is well known to engineers throughout the civilized world. There is no doubt in our minds that in economy, beauty of finish, and a happy combination of all the essentials to a perfect steam engine, it ranks among the first, not only in America but in the world. The reader will find some remarks upon this engine in the Scientific American for October 24, 1857, setting forth the advantages gained by the Corliss improvements; and during the twelve years which have succeeded the engine has had a history which its inventor may justly regard with pride. The engines exhibited this year show that American engineers are giving most careful and earnest attention to economy in the production of steam power, and although the number shown is not large, it, may safely be said that they represent all that is best in American steam engineering practice. Charles E. Emery, General Superintendent of the Fair (partially known to our readers through a series of articles on “Modes of Testing the Power and Economy of Steam Engines,” published in Vol. XIX. of the Scientific American), informs us that a competitive test of these engines will be made ere the close of the Exhibition. The judges have not, however, yet been appointed. We also notice in this connection Tapper's furnace grate bars, exhibited by L. B. Tupper, of New York, an illustrated description of which will be found on page 860, last volume of this journal to which the reader is referred. The bar is designed to secure the best draft, while its great depth enables it to conduct away the heat from the upper surface and prevent the grate from rapicfry burning out. Ample provision is also made for expansion and contraction. Another good thing appears to us to be the fire-proof cement, exhibited by the inventor, Mr. Barnum, of Troy, N. Y., intended as a non-radiating covering for boilers, steam pipes, etc. It is much cheaper than felt, in our opinion more efficient, and is said to be more durable. We are informed that it has been adopted in the Bessemer Steel Works at Troy, and is giving good satisfaction. One of the most important machines now running si the exhibition is lyall's positive motion loom. A description of this loom, published on page 17, current volume, of the Scientific American, with engravings showing its operation has been more extensively copied in American and foreign scientific and mechanical papers and periodicals than probably any article of a similar character ever published in this country. This is a sufficient evidence of the importance of the improvement, which we stated in that article, was consequent upon its radical character. The statements we then made in regard to it have all been sustained in practice, insomuch that some would-be authorities on mechanical subjects who took exceptions to the radical character of the invention, and even its originality, have been compelled to acknowledge all the points claimed in our descriptive article. We do not hesitate to pronounce this loom the chief attraction of the Fair to the manufacturing public. There are two on exhibition, one of which is running on dress silk and the other is weaving drugget six and a quarter yards in width. The operator of the drugget loom is a young girl, who is able to manage it with perfect ease, and can control its speed at will, the character of the work being the same no matter how low the speed may, within any reasonable limit, be carried. This is the o'nly loom in the world which can weave goods of any required width. Any one examining the beautiful silk texture, in the smaller loom, will be convinced of its value as a silk loom. We must however pass from this interesting feature of the department to a cursory review of the collection of wood-working machinery, undoubtedly the best ever displayed at any one exhibition in this country. One of the first improvements that catches jour eye in this department is the blind stile mortising machine, invented and patented by Leonard Worcester, and exhibited by the agent for its sale Mr. Martin Buck, of Lebanon, N. H. It does its work automatically, rapidly, and excellently ; and fully sustains all that was claimed for it in a descriptive illustrated article, published on page 152, current volume, of our journal. John J. Sanders, of New York, exhibits a combined sawing and mitering machine, very substantially constructed, and capable of performing a great deal of work very accurately. It was illustrated and described in our issue of October 7, 1868. The method of setting and securing the planing bits, or cutters, in this machine is peculiar and very effective ; it can be also applied to any tenoning, grooving, or planing machine, as it leaves a clear throat for the discharge of chips, unimpeded by bolt head or other devices, and does not necessitate the slotting of the bit which is simply a plain plate. Geo. L. Cummings, of New York, exhibits a fluting machine for banisters and all similar work, the peculiarity of whick is, that the cutter-head, once set, remains immovable, the work Leing lowered away from the cutters by an adjustable center. By#this means perfect uniformity in the work is secured. We were much struck with the simplicity and beauty of this machine. This gentleman also exhibits a saw table with a circular grooving saw, which works equally across or lengthwise of the grain, the saw being set inclined to the arbor. He also exhibits a 6-inch four-sided molding machine which is evidently capable of doing good work and a good deal of it. C. B. Rogers&Company, of New York, display a set of improved saw arbors, with self-oiling boxes. These arbors are made of the best English steel, and are elegantly finished. The boxes are cast on a solid bed, which connects the two together in such a manner that it is impossible for them to get out of line. They also exhibit an upright shaping machine, very neat and strong, with iron frame self-oiling steps and boxes. Also a pin and dowel machine with power feed, in which the operator has only to start the rod into the head and it will come out finished. Also a patent molding machine, working four sides at once, capable of making every variety of moldings, from the largest and most complicated down to the smallest. This machine also does double surfacing and matching to 10-inch, planing and matching staves, planing siding, sticking stair rail, etc. They also show a slat-sticking machine for blind slats, small moldings, etc., which works four sides simultaneously the same as the larger machines. An entirely new machine also exhibited by them is an outside head-molding machine, which works four sides at once, and does work from twelve inches deep by 9 inches wide, down to any required size. They claim that this machine will stick 20,000 feet per day. All of the machines exhibited by this firm are highly finished and substantially made. A. S.&J. Gear&Co., of New Haven, Conn., and Concord, N. H., exhibit an elegant and substantial Variety molding machine, a simple and perfect piece of mechanism for planing and cutting straight, waved, circular, and elliptical moldings, spiral work, and all irregular forms. The forms produced are of endless variety, graceful and elegant, and scarcely more expensive to produce than plain moldings. This is one of the most attractive machines displayed. Among planing, tongueing, and grooving machines, the principal firms represented are : John B. Schenck&Son, Matteawan, N. Y., and S. A. Woods, of Boston and New York. Some recent improvements on the Schenck Woodworth Machine were illustrated and described on page 241, last volume, of the Scientific American, to which the reader is referred. As now constructed it is a massive and powerful machine, easy to take apart and clean, and kept in perfect running order without difficulty. The Woodbury's patent planing, tongueing, and grooving machine is also a good machine, and worthy of special mention. This is exhibited by S. A. Woods, of Boston and New York, who also exhibit a very complete saw-gumming and sharpening machine, the working parts of which are constructed upon a tringular iron frame, upon the top of which is suspended a swing frame, the back end having a driving shaft (forming the hinge with tight and loose pulleys ; from this, power is transmitted to the arbor upon which is secured a vulcanite emery wheel. The arbor on which the saw is placed is so arranged that universal motion is readily obtained to accommodate any size or shape of tooth desired. The wheel is held away from © 1869 SCIENTIFIC AMERICAN, INC.