There are, as our readers are well aware, numerous machines in market for shelling corn, and some of these have justly won a large share of public favor. The corn sheller shown in our engraving has, however, some advantages which we have not met with in other efficient machines, the most prominent of which is its cheapness, the price of single machines being only five dollars. Another great advantage is its simplicity. It has no gearing, and there are no parts liable to get out of order. With these essential qualities of success it combines strength, durability, and efficiency. Its more important working parts are a toothed revolving shelling disk and a segment of a tube with Its concavity facing the shelling disk into which the corn is fed. This tubular segment is forced toward the shelling disk by a coiled spring which surrounds the shaft of the shelling disk, and acts between one of the bearings of that shaft and the segment, which thus forms a kind of adjustable hopper. The lower part of this hopper is expanded into a drum which surrounds the shaft, and also certain teeth of the shelling disk described below. The coiled spring above described acts against the outside of this drum to press it toward the shelling disk, and from the inner side of the drum projects a tube which surrounds the shaft, and is made of such a length that its end, when pressed up by the spring, reaches the face of the disk, and thus prevents the too near approach of the hopper to the disk. The shelling disk is armed with teeth, as shown in the engraving, which, engaging With the ear of corn as it is pressed forward by the hopper, tear off the grains from the cob. Between the drum of the hopper and the tube which surrounds the shaft above described, and which gages the approach of the hopper to the disk, are long teeth arranged concentrically with the shaft and parallel to it ; and the concave part of the hopper extending down past these teeth enables them to seize the ear and feed it down, thus bringing all parts of the ear under the action of the shelling teeth. The end of the tube which limits the approach of the hopper to the shelling disk is notched, so that grains of corn may fall through and not interfere with the action of this feature of the device by their lodgment around the shaft. The whole is attached to a wooden bench in the manner sliown, upon which the operator sits, the shelling disk and its attachments being actuated by a winch. The inventor states that the machine may be advantageously used for shelling green corn, though it will not accomplish the work as fast as it will shell ripe corn. Patented June 22, 1869, by J. P. Smith, whom address at Hummelstown, Pa. Brazilian Flour. The St. Louis RepaSlicara says that, at the request of the Union Merchants' Exchange, E. D. Morgan, Esq., of New York, shipped them two barrels of flour used generally by the higher classes in Rio de Janeiro—one barrel manufactured at Pesth, Hungary, and the other at Trieste, Austria— samples of which were exhibited on 'Change yesterday. The flour is very much like our Minnesota flour in tlie" feel," being exceedingly high ground, but is much whiter and entirely free from specks. We are indebted to Mr. Frank Feiner, of the Southern Mills, who was formerly a miller in Hungary, for a description of the process of its manufact'ure. The wheat is first dampened and remains so for twenty-four hours, when it is hulled, then run through a set of burrs that simply crack it ; then through a cleaning apparatus where it is cleaned and dusted ; then through another set of burrs ; then bolted, cleaned again, and back through the same process some fifteen times. During the first, four runs there is nothing taken out but the feed and coarse black flour ; after that the best flour commences to bolt through. The flour, it is asserted, will keep any length of time in a hot climate, but the process of making it is so slow and. so costly, that we have no idea that it will ever be made in this country, and we doubt whether its keeping or breadmaking qualities are any better than our best brands of St. Louis flour. A mill with slx run of burrs will only grind about 400 bushels of wheat in twenty-four hours ; while in St. Louis, a mill of the same capacity can flour over 2,000 bushels of wheat. The barrels that contain the flour are poor and not near as good in the cooperage as those sent from our mills. Improved Railway-Rail Splice and Chair. The use of fish-joints on railways is daily increasing, and there can remain no doubt in the minds of practical men that the employment of even the most costly forms which have been found desirable in all respects except cost, is economy in the long run. The invention we herewith illustrate, is, however, a combination of fish-joint and chair, and it is claimed that while it is an excellent and permanent joint, it can be made at scarcely greater cost than ordinary fish-plates, without the chair, and that its use therefore saves a large proportion; of the cost of chairs. The engraving is a section of the joint and ral, where one of the bolts, which hold the fish-plates flush to the sides of the rails, is placed. There are two of these bolts ; one on each side of the point where the rails meet. The upper edges of the plates support the heads of the rails, and their lower parts are formed into outward projecting flanges, as shown, lapping over the base of the rails and extending over and resting upon the sleeper. The outer edges of the projecting flanges are curved downward and formed into sharp ribs which euter into and engage with the wood of the sleeper, and resist lateral displacement. The strain is thus equally divided between the rail, chair, and sleeper, and does not, as in many forms of fish-plate heretofore used, come directly upon the bolts. Thus the nuts on the bolts do not so readily work loose. and when the de; vice is well spiked dow to'tfe' sleeper, it would seem almost impossible that the joint should not keep tight. Each plate with its ribbed base can be rolled in one piece, and is therefore strong and reliable. This invention was patented, through the Scientific American Patent Agency, August 10, 1869, by Thomas J. Adams. Address patentee at Marietta Iron Works, Marietta, Ohio, for further information. Eleetrolytic Insulation. In this system, patented by D. G. Fitzgerald, which is equally applicable to aerial, underground, and submarine lines, no insulating material, properly speaking—that is to say, no dielectric—is employed ; the lateral passage of the signaling current being prevented by a combination of metallic and electrolytic conductors, so arranged as to generate an electromotive force which opposes the escape to earth of the current. The principle upon which is based this" somewhat startling innovation in telegraphy, will be seen " on reference to the accompanying diagrams. Fig. 1 represents a battery of two cells. The outer vessel is of lead or copper, the inner vessel of the same metal, covered externally with zinc, and the central element is a cylinder of zinc. The two cells may thus be said to be included in one. Supposing the tensions of the poles of a single couple constructed of similar elements, and excited with dilute acid or a saline solution, to be respectively + 5 and — 5 when the couple is insulated, the tension of the zinc pole of the battery here represented will be — 20 when the outer vessel is in contact with earth. The same will be the case if hemp, slightly impregnated with a good electrolytic conductor, be interposed between the me-, tallic elements in lieu of the ordinary exciting fluid. It is to be observed that the zinc pole of this arrangement constantly retains its minus charge, although it is directly connected with earth by a series of metallic and electrolytic conductors. In the case of ten cells, similarly arranged, the free negative pole would constantly retain a charge at the tension' of — 100 ; and under no circumstances could electricity at this or a lower minus tension escape to earth by traversing the conductors intervening between earth and the central zinc element. It is evident, therefore, that a series of metallic and electrolytic conducton, disposed as shown in the diagram, is capable of effecting the insulation, or preventing the passage to earth of a negative charge, or of a cur rent from the negative pole of a battery. In order to distinguish this mode of insulation trom that which is effected by non-conductors of electricity, Mr. Fitzgerald terms the former "electrolytic insulation," and the latter " dielectric insulation." The rationale of the construction and working of an electrolytically-insulated telegraph line will be explained by Fig. 2, in which an underground cable, constituting an elongated battery analogous to that which has been above described, is supposed to extend between two signaling stations. The central conductor, both in the cable and the station batteries, will here acquire a negative tension, precisely as in the case of the battery shown in Fig. 1, since the arrangement may be regarded as simply a longitudinal e:1' _ tension of this battery. Until the signaling key at either station be depressed, no current can traverse the line and influence the receiving instruments ; the conductive circuit being otherwise incomplete, or the negative pole of the longitudinally-extende;' battery insulated from earth. To trace the of depress- ing the key at the right side of the figure, for instance, it is necessary only to consider that this key is in connection on the one hand with the line conductor, that is to say, with the negative pole of the battery on the left side of the figure, and on the other hand with earth, that is to say, with the positive pole of this battery, which is in contact with earth, By working tlie key at one station, therefore, the circuit of the battery at the other station is completed through the line, instruments, and earth, and signals are thus transmitted to the latter station. The fact that the circuit is completed in the case of the batteries at both stations, does not influence the result ; ware it otherwise, it would be easy to insulate from earth the positive pole of the battery at the signaling station by the same movement of the key which co-npletes the circuit of the battery at the receiving station. The electrolytic conductor employed in the construction of the cable, is hemp or other vegetable fiber which has been saturated with a saline solution and subsequently dried, though it still retains sufficient moisture to allow of its gf'ne-rating, by contact with aissimilar metallic surfaces, the electromotive force which opposes and prevents the lateral passage of the signalino- current. In overland lines, the electrolytic insulation of the conductor, instead of being continuous, is effected only at the points of support along the line, the dielectric air being, as in the ordinary system of overland construction, the principal insulating medium. Galvanized iron Tiles A new kind of meta roofing has been intro duced in France. The covering, instead of being continuous, like corrugated iron, zinc, or lead, is composed of sep. arate tiles formed of galvanized iron, and shaped something like our ordinary pantiles, but sus-l ceptible, of course, of various forms, according to convenience [or fancy. The tiles are remarkably handy. The metal being thin, they are easily cut to fit a sloping line of roof, corners, etc.; and they are fastened by a single nail of galvanized iron, with which is used a small leaden washer, to render the nail-hole perfectly tight. The advantages of such tiles are numerous. In the first place, they are not affected by fire, like zinc ; they do not oxidize, and their dilation and contraction have no effect on the roof. They cost from Sf. to 3f. 25c. per square meter, with 50c. for laying, making in all Sf. 50c. to Sf. 75c., without the scantling. This is about half the cost of a zinc covering. If the new tile presented any tone or picturesqueness, we should recommend them strongly ; as it is, we think nothing could be better adapted for roois out of reach of the eye. Their lightness and durability are invaluable qualities. It is right to add that the new tiles are patented by a company at Montataire.—London Architect.