C. G. W., of La.—You cannot procure a patent for making signs of glass. They are used quite extensively in this city. T. F., of Ohio.—It is supposed that the vegetable cell is similar in its action to the galvanic cell, but it is a mere supposition. The brown precipitate formed by immersing a zinc plate in a solution of blue vitriol, is a sub-sulphate of copper. J. S. M,. of N. Y.—The composition you mention for brass fixtures is lacquer. It is made with shellac dissolved in alcohol, and colored yellow with tumeric. B. B., of Ohio.—It is our opinion that the white lead and not the turpentine is the cause of painter's colic in painting with lead pigments. A portion of the lead may evaporate with the turpentine, and be inhaled by the painter; this action has been suggested. A. S. W., of N. Y.~A steam boiler will evaporate about as much water under sixty pounds pressure as under atmospheric pressure. If your boiler evaporates nine cubic feet of water per kour, it is nine horse power. J. H., of Ala.—You cannot freeze water by forcing condensed air into it. Dr. Gorrie applied refrigerating liquids for absorbing the heat from water to produce ice in his machine, As far as we have been able to obtain accurate information, no profitable ice-making machinery has hitherto been constructed. You may yet become the successful inventor. J. R. M. of-.You have given us no data for calculating the quantity of water which falls per minute therefore we cannot tell you the horse power of your waterfall. State your question correctly, and we will answer it. L. A.,of N. Y.—We have had a host of communications on the gyroscope, none containing anything of practical usefulness. We are acquainted with all the experiments related in your letter. B. M., of N. Y.—Practically we know that water wheels do more work, aud furnaces draw better during night than day, but we have not yet satisfied ourselves as to the reason why. Water will flow as fast over a nine foot as over a twelve foot fall. H. G. W., of N. Y—We understand that pipes are used upon several lake boats for carrying steam from boilers into the holds of the vessels for extinguishing fires. This method has been recommended as a safety adjunct by the supervising inspectors of steamboats. The idea of employing steam for extinguishing fires is old and well known. S. A., of Iowa.—Mere static pressure cannot raise water in tubes, as you suppose. As there are 6-26 lbs. of water in an inch tube 20 feet high, the total pressure of 3 lbs. on a piston in a four foot stroke pump making 40 strokes per minute, will raise water 20 feet high through the tube, and discharge its whole contents eight times every minute. E. A. D., of N. Y.—You cannot successfully heat water in a vat by placing the steam pipe upon its surface. ; Water will not conduct heat downwards; so that if you ' wish to accomplish your object, you should place the heating pipes at the bottom of the vat. A steam jacket when applied to an engine, is a casing filled with steam, for keeping the steam in the interior of the cylinder hot. It is known to be an economizer of fuel. Watt discarded it for a while, but resumed its use again for the above reason. J. W. S., of Ohio.—You are mistaken in supposing ; that telegraph companies could not use several wires twisted together for conductors, on account of their too great conducting powers. They have found that when one wire can do the work it is absurd to use more; just as it would be an erroneous policy to build and use three or f our tracks of railroad to do work that can easily be accomplished on a single track. A lightning rod is efficient according to its solid section; this is the opinion of Professor Faraday. S. & M., of Ky.—If you own a town, county, or State right in a patented invention, and any one should introduce the same improvement within your territorial limits, he is liable to you for damages, and you can sue and recover from him. It would be r diculous indeed if the purchaser of a patent right to a specific locality could be interfered with by the mere introduction of the invention from some other market, and have no remedy. G. H., of Del.—Constructing diaphragm pumps in the manner you describe has been done before, and is not, therefore, patentable. S. U. S., of 111.—By taking a common pencil, and holding it vertically to the eye, and observing how much of its length is necessary to cover the figure of a man at any known distances, say one hundred and two hundred yards, and then cutting notches in the pencil at the exact points, you will be able at any time, by this simple means, to approximate closely to the distance a person may be from you. A knowledge of this simple fact may prove of service in many cases. We know nothing of a bass viol operated by horse-power. It must be a curious affair. J. C. C, of Tenn.—We have never published an engraving of Halsted's turn-table. Wm. Howe has bad three patents granted to him on bridges. Two were issued in 1840, and have expired, and one was granted in 1846, and willnot expire, therefore, until 1860. C. C, of Pa.—Models sent to us without the name of the inventor attached, are liable to be mislaid and forgotten. The law requires the applicant's name to be put on his model. W. W., of N. J.—To preserve your boiler from rusting while it stands idle, introduce some oil into it just before it is stopped, and then run off all the water. A thin coat of oil will thus be left upon the metal to pro-I tect it. F. G. 8., of Mass..—Build your small boiler of a cylinder form, like that of a locomotive. Insert the steam pipe into its top when you have no dome. The power of an engine does not depend on the length of its stroke, but the pressure of steam, and the velocity and area of the piston. Cement for cast iron is composed of twenty pounds of iron filings, one ounce of sal ammoniac, and half an ounce of the flower of sulphur, made into a paste with water. Money received at the Scientific American Office on account of Patent Office business, for the weekending Saturday, June 12, 1858 :— L. H.. of La., $24; J. R., of Ohio, $25 : U. T. S., of Tenn., $30; T. G. Y., of N. Y., $25; G. W. S., of 111., $30; J. H. Q., of Mich., $24; A. S. L., of N. Y.. $100; A. R., of N. Y., $30; W. T., of Me., $55; R. H. C, of Ala., $30; G. W. B., of N. Y., $25 ; E. B., of Mo., $30; F. M., of 111., $30 ; W. H, B., of N. Y., $55 ; A. D., of Mich., $25; J. A A, of Texas, $30; B. & P., of Mass., $55 ; S. S., of L. L, $57 ; S. N. L., of N. Y., $30; J. F., of Mass., $81; C. W. & W. W. M., of 111., $15 ; H. N., of N. Y., $45 ; S. B. S., of Mo., $30; P. M., of 111., $30 ; J. J. W., of L. I., $30; M. D., of Conn., $250 ; O. D. W., of N. Y. ,$25; G. F. D., of Pa., $30; W. S., of Mo., $10; J. D., of Ohio, $20; W. W. H., of Texas, $30. Specifications and dra wings belonging to parties with the following initials have been forwarded to the Patent Office during the week ending Saturday, June 12, 1858:J. R., of Ohio ; L. H., of La. ; J. H. B., of R. L ; E. B., of Mo. ; F. B, N., of N. Y. ; J. H. Q., of Mich.; T. G. Y.,of N. Y.; J. L. S., of Tenn. ; A. D., of Mich.; T. E. McN., of Pa. ; O. D. W., of N. Y.; W. H. B., of N. Y. ; G. W. B.. of N. Y.; D. H., of N. Y. ; J. D., of Ohio ; H. N., of N. Y., (2 cases).; S. Iir, of L. L; J. F., of Mass., (3 cases); T. E. P., of N. Y. Literary Notices I Trow's ilEW York City t)iBE0T0RY. Compiled by H. Wilson We have just received this valuable Directory for the years 1858-9, containing 139.804 names, all of which have been collected, arranged, printed and bound in one month. To praise a Direcfcoiy would indeed be a work of supererogation as its value and usefulness are appreciated by every one. It is published b| X F. Trow, 377 and 379 Broadway, New York, for Wilson's Business Directory for 1858-'9—published by J. F. Trow—contains the names and addresses of all the business men of this city, classified under their respective occupations. The price is only $1, and no office or store should be without it. American Veterinary Journal—G. H. Dadd, V. S.Boston, Mass—This periodical which is so full of in, formation on all subjects relating to the veterinary art, and the treatment of cattle generally, is so cheap (only $1 per annum) that the owner of any quadruped, equine or bovine, must really be neglecting his own interests if he does not take it. The Ambrotype- By Chas. Seeley, A. M. This practical little treatise upon the art of producing collodion positives has attained a second edition. It is a very complete and correct manual, and should be in the hands of every photographer. The Musical World—R. S. Willis. Editor—The number for this week contains a beautiful piece of music, by R. Goldbeck, composed to the words, " Let me Weep," by Anna Freeman. It is also.full of interesting matter for the home circle or the desultory hour. The American Journal op Photography—Published at 424 Broadway, ^New York—This periodical has just commenced a new series, and there are many improvements with the new volume. It is an excellent magazine and very cheap. The Eclectic Medical Journal—Published by R, S. Newton, M. D., Cincinnati.—The June number contains some excellent articles upon medical subjects and hygiene, all, however, treated according to the theories ofthe so-called eclecticsdiool. Important to Inventors AMERICAN AND FOREIGN PATENT SOLICITORS.-Messrs. MUNN & CO., Proprietors of the Scientific American, continue to procure patents for inventors in the United States and all foreign countries on the most liberal terms. Our expe^'ience is of twelve years' standing, and our facilities are un-equaled by any other agency in the world. The long experience we have had in preparing apecificationa and drawings has rendered us perfectly conversant with the mode of doing business at the LFnited States Patent Office, and with most of the inventions which have been patented. Information concerning the patentability of inventions is freely given, without ehar^e, on sending a model or drawing and description to this office. Consultation may be had with the fir^xi, between nine and four o'clock, daily, at their principal office. 128 Fulton street, New York. We have lately established a Branch Agency on the corner ot F. and Seventh streets, Washington (opposite the United States Patent Office). This office is under the general superintendence of one of the firm, and is in daily communication with the Principal Office in New York, and personal attention will be given at the Patent Office to all such cases as may require it. We are very extensively engaged in the preparation and securing of patents in the various European countries. For the transaction of this business we have offices at Nos. 66 Chancery Lane, London; 29 Boulevard St Martin, Parip- and 26 Rue des Eperonniers, Brussels. We think we may safely say that three-fourths of all the European patents secured to American citizens are procured through our Agency. Circulars of information concerning the proper course to be pursued in obtaining patents through our Agency, the requirements ofthe Patent Office, &c., maybe had gratis upon application at the principal office or either of the branches. Communications and remittances should be addressed to MUNN & COMPANY, No. 128 Fulton street. New York. The annexed letter from the late Commissioner of Patents we commend to the perusal of all persons interested in obtaining patents :— Messrs. Munn & Co.—I take pleasure in stating that while I held the office of Commissioner of Patents, more than ONB-FOURTH of all THE BUSINESS of THE office came through your hands. I have no doubt that the public confidence tkus indicated has been fully deserved, as I have always observed, in all your intercourse with the Office, a marked degree of rromptness, skill, and fidelity to the interests of youcr ii. "avers. Yours, very truly, CHAS. MASON. WOOD-WORKING MACHINERY - LANE & BODLEY, Cincinnati, Ohio., manufacturers of all kinds of wood-working machinery. Morris' patent Wood-Benders, for any shapes or purposes—more effective and economical than any other in use. ARTESIAN WEIiliS-WANTED TO EMPLOY immediately, a practical artesian well-borer. Address WM. STICKNEY, Washington City, D. C. SPECIAIi EXTRAORDINARY OFFER-The great fifty cent Pictorial Monthly. The United States Journal commences its tenth volume with the July number; and determined, regardless of any outlay, to give it an immediate introduction into every neighborhood, we make the following special offer ;-To any person who will send us two subscriptions ($1), we will present either a beautiful copy of Fleetwood's Life of Christ, containing about 500 pages, elegantly bound, and profusely illustrated, or we will present a splendid copy of Livingston's Travels in Africa, superbly bound and illustrated; or acopvof the magnificent steel-plate engraving, " Signing oi the Death Warrant of Lady Jane Grey." The postage on the books is 24 cents each, and on the engraving 12 cents, which must accompany the order. If anvbody is fearful that the above offer will not be carried out, they can deposit the amount and postnge with their postmaster, to be forwarded by him on receipt of the premium and first number of the paper. We will also send our catalogue of rich offers. J. M. EMERSON & CO., 406 Broadway, New York. FOR SAIiE AT A BARGAIN-ONE NEW 13 ft: Iron Planer, weight 10,000 lbs. One new 18 ft. Engine Lathe, swing 30 inches. One second-hand Engine Lathe, swing ^21 inches. One Upright Drill, six Shaft Straighteners, six Bolt Headers. Forparticu-lars address or inquire of WM. T. SCRANTON, New Haven, Conn. SD. BARNETT, MALLEABLE AND GREY Iron Foundry, Hamilton, corner of McWhorter St., Newark, N. J. Orders promptly attended to. PATENT GRATE BARS-FOR STEAMBOAT and Stationary Engines—manufactured and supplied by the Salamander Grate Bar Co., office 30 Pearl St., New York. TWEED'S PATENT PORTABI.E AND STAXt TIONARY STEAM ENGINES, unequaledlorsim-plicity, durability, and economy. Birkbeck's improved Steam Pumps, Portable Steam Saw and Grist Mills ; second-hand engines and boilers. Most improved machinery of all kinds, furnished by JOHN A. REED, No. 172 Broadway, corner of Maiden Lane, New Yorlc City. These machines have no rival.—[Scientific American. WHEELER & WILSON'S SEWING MATT CHINES, 343 Broadway, New York, received the highest premiums awarded in 1857 by the American Institute, New York; Maryland Institute, Baltimore ; and at the Maine, Connecticut, Illinois, and Michigan State Fairs. Send for a circular containing editorial and scientific opinions, testimonials from persons ofthe highest social position, &c. MACHINISTS' TOOLS FOR SALE AT HALF PRICE—I will sell the remainder of the tools belonging to the estate of John Parshley at half price, if called for soon. Said tools are new, and in good order. They consist in part as follows :—One 16 foot planer. 10 hand lathes, 2 spliner drills, 13 No. 1 drills, 1 bolt header, 1 shaft straightener, plane centers and jaws, chucks, all izes; also 8 of Foster's building block machines. N. D..SPERRY, Trustee, New Haven, Conn. BELTING AND PACKING - Niagara Falls Paper Manufacturing Co., Niagara Falls, April 20, 1858. United States Gutta Percha Co. : We duly received the^Gutta Percha Belting ordered from you, and after giving it a thorough test the past winter, on our heaviest engines, constantly exposed to water, ice and oil, and making 140 to 160 revolutions per minute; and again on two of our largest ''Gwynne Pumps," making from 600 to 700 revolutions per minute, they have given us entire satisfaction, and we think it decidedly the best belting we ever used, and you may look for our future orders as required. S. PETTIBONE, Treasurer and Superintendent. For sale by the UNITED STATES VULCANIZED GUTTA PERCHA CO., No. 66 Liberty street. New York. CIRCULARS WITH CUTS, ILLUSTATING steam engines and machinery for making lumber, shingles, staves, heading chairs, bedsteads, and wheat-cleaning machinery, bran dusters, &c., sent for a postage stamp, by applying to L. A. SPALDING, Lock-port, N. Y. WOODWORTH PLANING MACHINES, f f Mortising, Tenoning, and Sash Machines, and a full assortment of wood-working machinery, at greatly reduced prices. Address CHARLES H. feMITH, 13 North Third st., Philadelphia, Pa. FIFTH EDITION-CATALOGUE CONTAIN-ing 250 illustrations ff Mathematical, Optical and Philosophical Instruments, w^th attachment of a large sheet representing the Swip,3 instruments in their actual size and shape, will be delivered, on application, to all parts of the United States, by sending 12 cents in postage stamps. C. T. AMSLER, No. 635 Chestnut st., Philadelphia. WOODWORTH PLANERS-IRON FRAMES to plane 18 to 24 inches wide—at $90 to $110. Foi sale by S. C. HILLS, 12 Piatt street New York. PHILADELPHIA RIVET WORKS~MANU facturers ofthe celebrated P brand. Boiler, tank, and gasometer rivets, of every diameter, length, and head. PHILLIPS & ALLEN. EMPLOYMENT—TO SELL A NEW AND novel invention to defeat pickpockets. Write tc DICKINSON & BATE. Hudson, Mich. CLARK'S REGULATOR-FROM TEN TO twenty-five per cent saving in fuel is guaranteed in the use of Clark's Patent Steam and Fire Regulators ; besides giving the most perfect regularity of power at any desired pressure, and no fear of explosions. Send for circular at 229 Broadway, New York City. E. R. PRATT, Secretary. FIRST-RATE TENON MACHINES FOR SALE LOW-Medal awarded by the American Institute, New York. C. P. S WARDWELL, Lake Village, N. H. HARRISON'S GRIST MILLS-20,30, 36 AND 48 inches diameter, at $100, $200, $300 and $400, with all the modern improvements. Also, Portable and Stationary Steam Engines of all sizes, suitable foi said Mills. Also, Bolters, Elevators, Belting, &c., &c. Apply to S. C. HILLS. 12 Piatt st., New York. CLOCKS-TOWN CLOCKS OF ALL SIZES, Regulators and Timepieces f or all purposes. Dials for illuminating. VOSBURGH & CO., Agec ts. No. 26 Liberty street, New York. J OHN SHERRY, Manufac turer, Sag Harbor, N. Y. Steam engines, steam boilers, Steam Pumps. Saw and Grist Mills, Marble Mills, Rice Mills, Quartz Mills for gold quartz. Sugar Mills, Water Wheels, Shafting and Pulleys. The largest assortment of the above m the country, kept constantly on hand by WM. BURDON, 102 Front street, Brooklyn, Harrison's 30 inch grain mills-Latest Patent.-A supply constantly on hand. , Price $200. Address New Haven Manufacturing Co., New Haven. Conn. The works of the aubin gas co., (GeneralOffice, No. 44 State st., Albany, N. Y.,) as now perfected, are adapted to all materials and localities, and are in successful operation in villages, factories, and private dwellings. For full information as to cost, probable income of public works, &c., apply as above. For plans, &c., see Scientific American of March 13th. Second-hand machinists' tools-Consistingof20 Engine Lathes, 9 Iron Planers: 4 Upright Drills, Hand Lathes, Clmck Lathe, Gear Cutters and Vices, all in good order, and for sale low for cash. For particulars, address FRANKLIN SKINNER 14 Whitney avenue. New Haven, Conn. Machine belting, steam packing, ENGINE HOSE.—The superiority of these articles, manufactured of vulcanized rubber, ia established. Every belt will be warranted superior to leather, at one-third less price. The Steam Packing is made in every variety, and warranted to stand 300 degs. of heat. The hose never needs oiling, and is warranted to stand any required pressure ; together with all varieties of rubber adapted to mechanical purposes. Directions, prices, &c., can be obtained by mail or otherwise, at our warehouse. NEW YORK BELTING AND PA(^KlNG COMPANY. JOHN H. CHEEVEK, Treasurer, No. 6 Dey street, New York. Peck's patent drop press-FOR Jewelers, tin and copper workers, gun and other forgings, &c., manufactured by the patentee, MILO PECK & CO., New Haven, Conn. For sale-AN EIGHT-HORSE UPRIGHT engine, boiler and fixtures, second-hand, nearly new, all in good running order. Address H. B. MATHER, West Norwalk, Conn. Second-hand machinery AT VERY low prices for cash.—Steam Engines, Slide Lathes, Planing Machines, Drills, Slotting Machines, &c.; also a variety of Mortising, Tenoning, and Sash Machines, &c., all warranted in good running order. Address CHARLES G. WILLCOX, 87 North Third st., Philadelphia, Pa. Slide lathes, iron planers, UP-right Drills, Slotting and Boring Machines, Universal Chucks, and a large asg rtment of machinists' tools, at greatly reduced prices. Address CHAKLES H. SMITH, 135 North Third st., Philadelphia, Pa. New haven manufacturing co.-Machinists' Tools, Iron Planers, Engine and Hand Lathes, Drills, Bolt Cutters, Gear Cutters, Chucks, &c., on hand and finishing. These tools are of superior quality, and are for sale low for cash or approved paper. For cuts giving full description and prices, address **New Haven Manufacturing Co., New Haven, Conn.' Machinery.-IF YOU WANT THE BEST Portable or Stationary Steam Engines, Wood-worth's or Daniels' Planers, or any other kind of machinery for working wood for the least amount of money, address HARRISON FLINT, Danbury, Conn. Engraving on wood and mechaniCAL DRAWING, by RICHARD TEN EYCK, Jr., 128 Fulton street. New York, Engraver to the Scientific American. Page's patent portable circular SAW MILL, and Portable Steam Engines and Boilers mounted on substantial wheels, ready to saw lumber, thrash wheat or gin cotton. Our Mills will saw from 2,000 to 10,000 feet per day. Add ress GEO. PAGE & CO., Baltimore, Md. Woodworth planing machines— Having over $40,000 worth now completed, I will sell, from this time henceforth, at a very reduced price, and am ready to construct any sizes not on hand at short notice. JOHN H. LESTER, 57 Pearl st., Brooklyn, .Long Island. Lap-welded iron boiler tubes-Prosser's Patent.—Eveiy article necessary to drill the tube-plates and set the tubes in the best manner. THOS. PROSSER & SON, 28 Piatt st, New York. Oil I oil: OILI-FOR railroads, STEAMERS, and for machinery and burning. Pease's Improved Machinery and Burning Oil will save fifty per cent., and will not gum. This oil possesses qualities vitally essential for lubricating and burning, and found in no other oil. It is offered to the public upon the most reliable, thorough and practical test. Our most skillful engineers and machinists pronounce it superior and cheaper than any other, and the only oil that is in all cases reliable and will not gum. The Scientific American, after several tests, pronounced it " superior to any other they have ever used for machinery." For sale only by the inventor and manufacturer, F. S. PEASE, 61 Main st., Buffalo, N. Y. N. B.—Reliable orders filled for any part of the United States and Europe. Vail's speedwell iron works, Morristown, N. J., manufacture Craig's Patent Double-acting Balance Valve Oscillating Steam Engines both stationary and portable, Knowles' Patent Muley, Portable, Gang and Re-sawing Mills, Sugar and Chinese Cane Mills and Sugar Pans, Grist Mills, Mill Irons, Rich's Water-wheels, Forgings and Castings. Orders for the above, and all descriptions of labor-saving ma-chinerv will receive prompt attention. JOHN H. LIDGERWOOD & CO., No. 9 Gold street. New York. Corliss' patent steam engines-About 250, most of them from 40 to 400 horse power, are now in operation. On application, pamphlets will be sent (by mail), containing statements of responsible manufacturing companies where these engines have been fumished,for the saving of fuel, in periods varying from 2}4 to 5 years. Boilers, shafting, and gearing. "^CORLISS STEAM ENGINE CO., Providence, R. I. Mowing and reaping knives OF every description manufactured by C. H. LAME, No. 407 Cherry st., Philadelphia, Pa. First premium awarded by the United States Agricultural Society for mowing and reaping knives. Patent office models CAREFULLY made on scientific principles, at low prices, by H. SHLARBAUM & co., 800 Broadway, New York, llef-erences at'.the office of this paper.
This article was originally published with the title "Correspondents" in Scientific American 13, 41, 327 (June 1858)