Under this head the Independent Democrat, of Concord, H., gives us a long description of what the editor supposes to be a new way of transmitting power, specially useful in cities as a substitute for steam, the invention of Horace Call, of that city. By moans of water wheels and pumps, air is to be compressed at the river bank and conducted in pipes to the city shops. Here the air discharges into the bottom of a tank, and bubbles up like a boiling caldron. Within the tank is a bucketed wheel, so arranged that the buckets will receive the ascending current of air, the force of which will turn the wheel and drive the machinery of the shop. "The philosophy of the power," says the Democrat, "is simple. The air displaces the water in an upward cur rent, equal to the weight of water down. It is so simple that it is a wonder that it has never been applied before. " The possibilities of this invention aff'ord a wide field for speculation, and one which we will not enter upon to-day. Whfn we consider that it probably costs $50,000 a year to operate the stationary engines in this city, while a river with 10,000-horse power runs through it, unused, the magnitude of an invention which proposes to make it available at a comparatively small expense, is one which challenges the attention of mechanics and scientific persons." There appears to us nothing in the above invention which warrants the great expectations expressed by our New Hampshire cotem-porary. The practice of driving machinery by compressed air is very old. Ordinarily it is wanting in economy as compared with tle direct employment of water or steam. But in inaccessible locations, in mines, and tunnels, it is used to advantage, serving for ventilation as well as power. In the Hoosac and Mont Cenis tunnels the drilling machines are driven by air, which is compressed by water power and carried long distances in pipes to the drills. The only novelty in Mr. Call's improvement lies in his tank and air wheel; but this form of air engine carf hardly be as eff"ective as the ordinary machines. The resistance of the wheel revolving in the water, and the friction of the rising air will about equal, we should think, the friction of a well-constructed piston engine. Tlie Ponsard Process ot Smelting Iron Ore, This is a French improvement, if indeed it shall prove to be in practice a real improvement. The chief feature of the Ponsard process, is that the ore is pulverized and mixed with pure coal or carbon, and then placed into tubular crucibles, heated from the outside. By thus protecting the ore from the direct action of the fuel employed for heating the crucibles, inferior combustible matter can be used and a certain economy thereby effected. By an arrangement of the furnace, gray or white iron, or even steel, can be produced at will. The furnaces can easily be converted into puddling furnaces into which the metal can enter at one side and run out at the other, prepared for being submitted to the rolling mill. Suit for a Million. Andrew Whiteley, who for a long time has been contending with the Commissioner of Patents for certain reissues, has finally entered suit against that ofiicial. In his declaration he sets forth that, in various patent cases in which he was assignee of Gage, Weeks, Haines, and others, for improvements in harvesters, etc., he obtained certain orders of Judge Fisher, of the Supreme Court of the District of Columbia, directing the Commissioner of Patents to take certain evidence as to novelty, to reissue certain patents, and to antedate others; that, in consequence of these proceedings, he has been compelled to lose time, opportunities of making money, and to employ counsel, by reason of which he is a large loser. He therefore jrings suit, laying his damages at one million dollars. If Mr. Whiteley should succeed in getting j udgment for ;he amount of damages claimed, we imagine that it might yo hard with Commissioner Fisher to raise the funds.* Darvallio's Painting; of tlie Grand Canyon of tlie Colorado River, Mr. S. N. Carvalho, patentee of a very excellent steam mper-treating device and an artist of considerable merit, Tave a private exhibition of a new painting of his, on Friday 3vening, September 3d, at his studio, 765 Broadway. The subject is a view of the Grana Canyon of the Colorado River, md is of interest from the fact that the sketches were taken by Mr. Carvalho on the spot and while attached to the Fremont expedition as photographic artist. The stern and impressive grandeur of its everlasting rocks made such an LUiipression on Mr. Carvalho that he took sketches of them 181 from various points of view with great trouble and at iuucIl personal risk. The picture represents the canyon at the bead of Diamond Creek, where the vast rocky walls rise abruptly to the hight of from 3,000 to 6,000 feet. At the bottom of this gloomy and terrible abyss flows a stream of dark water, flecked here and there with foam. In the background is a line of lofty bluff's, many of them crowned with masses of rock of enormous size and fantastic shapes, in which domes, towers, spires, and minarets are faintly outlined.