United States Circuit Court.-Southern District of New York Mundy vs. Lidgerwood Manufacturing Company. When an inventor merely Brings an old element into his machine, he makes no invention; but where he does more -- dispenses with certain parts, duplicates others, rearranges and simplifies the machine -he must be held to have made an invention. When a patent is for a combination, one element of which is a gear wheel with a cone supported in a peculiar manner, and the defendant uses the gear wheel with the cone, but the latter is supported differently, though the elements employed by the defendant are the equivalents of those of the complainant in the patented combination, Held that the defendant takes the complainant ' s combination and infringes his pate nt. The New York Produce Exchange. The dimensions of this great building, which was illustrated in the SCIENTIFIC AMERICAN for May 10, are as follows: Length on Broadway and Whitehall Street, 307 feet; on Beaver Street, 150 feet; and on Stone Street, 149 feet; the tower being 40 by 70 feet, and 200 feet high. The aggregate floor surface in the building is 7 acres, and the Board Room proper is 220 by 140 feet, 60 feet high in the center, and lighted by 23 windows, each 31 feet high, and a skylight over the center. The cost of the site and the pile foundations was 1,000,000, and the total cost of building and site about 3,000,000. In this great building, by the aid of the cable, the telegraph, and the telephone, the principal commercial emporiums of two continents are brought into instantaneous commercial intercourse. Substantially all the agricultural productions exported from New York are bought and sold on the floor of the Exchange, and how large this business is may be estimated from the fact that in 1880 there was received at New York 59,000,000 bushels of wheat, 61,000,000 bushels of corn, and 5,000,000 barrels of flour; and in addition to these articles the transactions in beef and pork and their related products are always on an immense scale. New Stone Saw. A new sort of saw for cutting stone is described in La 8emaine des Oonstructewrs, which seems to have advantages over those now commonly in use, and is easily and cheaply made and operated. In place of the ordinary long steel blades, supplied with sand to enable them to grind their way into the stone, the new machine presents only a slender endless cord, composed of three steel wires twisted together, which is stretched over pulleys in such a way as to bring the lower portion horizontally over the stone to be cut. The frame carrying the pulleys is movable, so that the cord can be brought into contact with the stone, or lifted away from it, at pleasure, and the whole is kept in rapid motion, while water falling in drops from a reservoir above serves to moisten the stone. The three wires which form the saw differ from the ordinary kind in being square in section, and by twisting into a cord they are so turned as to present a succession of oblique cutting edges, which act, when set in motion, in nearly the same way as so many small chisels, while the rapidity with which the blows follow each other probably adds to the effect. American Institute ofElectrical Engineers. At the call of a number of prominent electricians a meeting was held on the 13th of May, in the rooms of American Society of Ci vil Engineers, New York, and the organization of the above named society was effected. The first of its kind in this country, it bids fair to have a prosperous career, and will undoubtedly tend to promote the interests of all those engaged in electrical pursuits That the society is a representative one, will be seen by the list of officers elected which is as follows: President: Dr. Norvin Green. Vice-Presidents: A. Graham Bell, Charles T. Cross, Thomas A. Edison, George A. Hamilton, Charles H. Has- kins, Frank L. Pope. Managers: Charles F. Brush, William H. Eckert, Stephen D. Field, Elisha Gray, Edwin J. Houston, C. L. Hillings, Frank W. Jones, George B. Prescott, W. W. Smith, W. P. Trowbridge, Theodore N. Vail, Edward Weston. Treasurer: Rowland R. Hazard; Secretary: Nathaniel S. Keith. Incorporation ofa Bridge Building Company. The firm of Clarke, Reeves&Co., proprietors of the Phmnixville (Pa.) Bridge Works, has been merged in a corporation under the style of the Phmnixville Bridge Company. The works of the company have a capacity of thirty to thirty- five thousand tons a year, and among their productions have been the Kinzua Viaduct, numerous new bridges for the West Shore Railway, and the structures of the Second and Ninth Avenue elevated railways of New York city. Mr. David Reeves is president of the company, and Mr. Adol- phus Bonzano is vice-president and chief engineer. 1884 SCIENTIFIC AMERICAN, INC 322 Jeitutific rntricnu [MAY 24, 1884. The Artificial Light of the Future. In his Science Notes, in the current number of the Gentleman's Magazine, Professor Mattieu Williams says: My note on th is subject last J uly* was preceded by one 011 the researches of Professor Radziszewski. I now learn that he has actually separated the luminous matter of thePelagia noctiluca, one of the multitude of species of marine animals that appear like little lumps of jelly, and produce the phosphorescence of the sea. He evaporated to dryness 180 specimens; and from the residue he dissolved out (by means of ether) a peculiar kind of fat, which, mixed with potassa, gives out, when shaken, phosphorescent flashes. This is exactly what happens to the living animal. When quiescent it is not luminous; but if shaken or rubbed, it flashes. I have collected and examined a great variety of these animals at different times; the most remarkable occasion being one morning after a magnificent display of marine luminosity in the Mediterranean, a few miles off the shore of Algiers. The surface of the sea was incrusted, I might almost say, with countless millions of small jelly-like creatures, of spherical, ovoid, oblong, dumb-bell, aDd other shapes, varying in size from a mustard seed to a pea. A bucketful of water taken over the ship's side appeared like sago broth. They were all internally dotted with a multitude of what I suppose to be germs, that would be liberated on the death and decay of the parent. The practical importance which I attach to the study of the luminosity of these creatures is the fact that they supply light without heat. The costliness of all our present methods of artificial illumination is due to the fact that we waste a largely disproportionate amount of energy in producing heat as well as light. This wastefulness may be illustrated by supposing that we obtain a pound of the phosphorescent fat of the noctiluca, and divide it into two equal halves; making one-half into candles to burn in the ordinary manner, and using the other half to give out its light by cold phosphorescence. I am not able to give precise figures, but believe that I am well within the truth in estimating that the candle would dissipate 95 per cent of the potential energy of the flit in the form of heat; giving but 5 per cent of the amount of light that the other half pound would emit as cool phosphorescence. Let us, then, hope that Professor Radziszewski will continue his researches, and discover the whole secret of both the analysis and synthesis of this fat; and that ofthe glow-worms, the fire-flies, etc. Now that we can supply the confectioner with the flavors of almonds, raspberries, jargonelle pears, nectarines, etc., and imitate the perfumes and the richest colors of nature's sweetest and brightest flowers, all by the chemical manipulation of coal tar, we need not despair of solving the chemical problem of transforming mutton suet, or palm oil, or vaseline into glowworm or noctiluca fat, , to be used for illuminating purposes. --Journal of Gas Lighting.