H. W. G, of N. C—We published a description of a flying ship in Vol. 1, Sci. Am., of a double cone form ; bird-form balloons have been tried before. The same ideas as those you have presented have been carried out in the parachute. We assure you that the only theory to attract attention and command success is to do the thing. J. T,, of C. W.—Look on another pag for something suitable aa an answer to your letter. C. B., of N. Y.—There is a book sold by J. Wiley, this city, named the u American House Carpenter;“ there is also “ Downing's Cottage Architecture,“ and Ranlett's. If there is a bookseller in your place he will be the best person to get them for you. J. R., of Mich.—Your improvement in working muley-saws, we believe, is good—so far as we can learn, it appears to be new and patentable. J. Z. P., of N Y.—Instruments for measuring the height of mountains and the depression of valleys, are very common, but you may have an improved apparatus notwithstanding. J. P., of Conn —We never heard of steel being cast into files, or any thing of the kind. J. S-, of Mass.—We have not a copy of the numbers on hand ordered by you. A. P. S.j of Ga.—We are glad the Ear Trumpet sent to you in 1849 pleased you, but we cannot be at the trouble of superintendingthe construction of another; we are not in the “trumpet“ business at present; S. H., ofWis,—The novelty of your arrangement of the friction rollers we fail to perceive, your assertion to the contrary notwithstanding; we would not advise you to make an application for a patent. B. P. C, of Ky.—We should be very happy to receive communications from you on the subject of Kiln Drying, and plans of your mode of constructing the furnaces we could probably publish. A.' M. B., of Vt.—Por raising very heavy weights, such as placing masts in a ship, or boilers on board a steamer, shears, and not a derrick, are preferably employed. W. H. C, of Mo.—By sending us $2 we will forward you the claims of both the parties. Patent Laws sent. P. L P., of R. I.—Send on your model. H. M. & Co., of Mass.—There is no doubt but that both of the af are good, and you had better address the parties direct—not through us. C. B., of Ga.— On page 76, Vol. 6, Sci. Am., you will see an engraving of a mechanical cradle, which we believe to be precisely like your plan; it was patented. J. 0. R , of Pa.—Jennings' rifle is no doubt a good one, but we are not so well acquainted with it as with Marston'a, the Ittttwrws.now ta-lwrrflrEt-ate- 0. B. Q., of Wis-—I* requires but about one horse power to drive an Alcott lathe, and it will turn out 400 fork or 1500 broom handles per diem. L, G., of N. Y.—There is scarcely a doubt butthat your improvement in railroad axles is new and patentable, but we would not venture an opinion as to its practicability. C. B. H., of N. Y.—The plan you suggest for preventing railroad accidents has been well known to us for two years. A patent was taken out for enclosing the axle in a case ; the principle being precisely the same as Mr. Pinch's wheel, illustrated in the last number ; the construction is different of course. J. C. B., of N. H.—We can give you no better information than we have already done, and if you wish to satisfy yourself as to the utility of the invention, you had better give it a practical test. L. W. J., of Iowa—Your friend's plan for changing motion is a device on which, no doubt, twenty applications for patents have been made already. There is nothing new in it W. D. A., of Ohio—If you have a plan by which trains of cars running at the rate of 40 miles per hour, can be kept in communication with each other by telegraphing, you no doubt have an important invention. The Telegraph is owaed and used by some R. R. Companies now, for their convenience, but the communications are only made from the stations—not from the train. You should secure your patent at home and abroad, simultaneously. 1. L\, of Ohio—The diagram of your hair beater represents a patent churn we had exhibited to us last year. There is nothing patentable in your apparatus. A. M., of Phila.—An engraving of your machine would cost $12. We have a specification and drawing of it, so if you desire us to get up the views on wood you have but to send us the money. J. H. G., of Pa.—Your caveat was filed April 1st, 1852, D. H. S.j of Pa.—We do not know of a single useful work on tin, and copper smithing. Give your zealous attention to the practical part of the business, and become a good workman; and read useful works, J.*W., of N. Y.—The copper plates for daguerreotype pictures are made by rolling, but being imported we do not know the price of the machinery. J.W., of Mich.—By hard water we suppose you mean that impregnated with lime ; it is healthy if jthe lime is in minute quantities. Magnesian waters are unhealthy. Lead pipe is safe with your “ hard “ water; cast-iron pipes are employed for our IE main “ pipes. They will last for a long time and are not liable to oxydize, but wrought iron pipes are not suitable. J. G., of Boston.—We receive all our claims officially from the department, and always publish all that are sent to us. We can never be induced to suppress any one's claims under whatever pretence V they may advance. D. M. D., of Pa.—We know of no better work on millwrighting than those you mention as having. M. K.s of Mass.—Your plan of tightening millstones is the ordinary plan used in nearly all modern built mills. Your tack hammer maybe new, send one on that we may examine it. G. W. L., of Pa.—We have examined the model of your wheel. It contains nothing new or patent-able, and you are advised not to make an application. G. L. L-, & Co., of Ohio.—We think your improvements in candle moulds to be new and patentable. You had better send a model. J. M. N., of Pa.—Your plan for a perpetual motion is excellent, but it won't go. It cannot be that you are a careful reader of the Scientific American, or you would know better than to submit diagrams of a perpetual motion for our opinion. J. M. G., of Va.—Steamboat wheels with the paddles so arranged as fo enter the water vertically, is about as old an invention as we know of. P. S., of Conn.—We have not the information you want now, if we obtain it you may expect to see it in print for your benefit. W. H. M.. of Ind.—We can execute and publish an engraving of your machine for $12. Money received on account of Patent Office business for the week ending Saturday, Jan. 22 : 0. &R-, of N.Y., $15; J. M., of Me., $10; C. S. B., f L. I, $10 ; J. E. N., of N. Y., $30 ; H. B., of N. Y., $100 ; I. P. W.. of Mass., $30; G. S., of Conn., $10 ; W. Z., of 111, $55 ; A. H. B.,of N. J., $150 ; H. T., of N Y-, $50 ; I*. E-, of Conn., $25 ; W. S. P., of Ct., $25 ; S- R. & H., of N. Y., $40 ; H. E., of N. J., $27; J, E. E., of N. Y., $55 ; P. G. G., of N. Y.3 $55. Specifications and drawings belonging to parties with the following initials have been forwarded to the Patent Office during the week ending Saturday, Jan. 22: J. R., of N. J. {2 cases) ; D, E., of Conn.; W. S' P.. of Conn.; T. S , of Ohio ; J. E, E., of N. Y. ; H E.', of N. J. ; B. H,, of N. Y. ; P. G. G-, of N. Y.