C. P., of Iowa—Instead of charging jou a, dollar for the information you solicit, we have credited you for 6 month.8 subscription, and sent a back numbar of the paper containing just the information you solicit: hope every one of the 26 copies you will receive may be worth a dollar toyou. W. E. L, of Ohio—We duly received and filed your letter respecting the "syphon;" our opinion has not been chaDg&d. We have no knowledge of the publication to which you refer. You should submit your inquiry to some lawyer in your place ; it does not come within our province. C L , Jr., of Ot.—It would depend entirely on your management of the affair after it was patented ; many fortunes have been made on worthless patents, while meritorious inventions have lain dormant for want of energy and capital to introduce them to the public. The pecuniary worth of mostpatents lies in the ability of the managers of them. M. 0. R , of St. Louis—A set of volume 6 was sent to you, addressed to the care of Mr. Byrne,*onthe 7th ult. S C. M , of Ind — We sent your LettersPatent and wood engravings to you by Express on the 29tli ult. $12 received, P. P of N. H., and F. L, A., of Ct — Tour letters were both received by one mail, each asking the same question ; in reply to them we would state that the plan of arranging brakes to act upon the upper periphery of the wheel, using the weight of the car as part of the applied power, has been very often suggested to us. L. & L., of N. Y.—We] must have the first use of the cuts or we cannot publish them at all. As soon as you send us a better drawing and a more full description, accompanied with $12, we shall prepare the engravings, and will insert them soon. S. T. T., of N. Y.—Your plan for dressing mill stones has been tried but found not to be practicable. A. C. R., of Ohio—We do not remember what your communication wa3, but presume, if you sent one here and it was not inserted, it was thought not of sufficient interest to pay for the room it would occupy. E. F., of N. J.—Your chemical balance appears to be new, usefuland patentable. 8- B., of Ind.—You spoke too late, your specification and drawings have been filed in the office several weeks. Wehave nothing to get up an engraving from at present, H. G. H-, of N. Y.—Messrs. Birbeck, in this city, make good boilers, as do Messrs, Psase & Murphy; in fact they are built in all our large engineering establishment. Initial horse-power is a very- indefinite terra.' -IFmtr-wa-gintrnt ttrvh borer TBtttlr~2" feet stroke will be about 5 1-5 horse-power, that is, at 21 lbs. pressure. D. S., Jr., ofN. H.—The machine you describe would probably infringe upon the Blanchard Lathe. W. B., of Pa.—The best Ms for wet tan bark is a round one, feut the form of flue will not remove the evil of the vapor. A. B.. of Pa,—Your plan for a grain separator, we think, is new and patentable, but the butter preserv-i er, we think, lacks sufficient novelty. The pump matter we will take into consideration. C. W- B., of Ohio.—The diagram you sent of the harvesting machine, we believe illustrates a new invention, but we have our doubts of its being as good as many others. Your plan for taking and registering votes was illustrated in Vol. 2, Sci. Am. r C. E. W., ofS C — We have a new edition of the Patent Laws in press, which will be out and ready for mailing in a few days. The coating of lightning conductors with block tin Would be no more patentable than covering a sheet iron dish with the same material, and thus rendering it a " tin pan." J. A. H., of Pa., and J. M. J., of Ky,—We have none of the back numbers previous to January, with which we can furnish you. [t~r= Owing to the illness of one of our nnmber, who usually attends to corresponding with inventors, we are necessarily obliged to let several letters remain over unanswered until next week. Money received ou account of Patent Office business for the week ending Saturday, Jan. 29 : J. T., of 111 , $55 ; V. P. & B. K., of N, Y., $10 ; F H., of Pa , $55 ; E. St J , of N. Y., $55 ; M. B D of Pa., $39; H. GK B., of Tenn., $50; L. D., of N. Y , $30 i J. M. EL, of N. Y , $30 , W. T. B. M., of N. Y $100; W. T., of N. Y., $20; J. C. S., of Pa., $30: E. G H.,of N.Y.,$30; J. S-, of Ky., $10; E. C. B , of N. Y., $25; J-B. D ,of N. Y.,$30; W. C, of Mass., $30; H. W. W., of N. Y., $20 ; E B. W , of N H $20 ; B. B., of N. Y., $25 j S. &. L , of Mass.. $30 : J.McM., of Ky., $20; G. S., of N. Y., $15. Specifications and drawings belonging to parties with the following initials have been forwarded to the Patent Office during the week ending Saturday, Jan. 29: 8 &. L , of Mass ; F. P., of Mo.: J. C. S, of Pa,: W. T., ofN. Y.j W. McB , of Ohio ; B. BM of N. Y J. McM., of Ky.; G. K., of N. Y.; J. K.. of N. J. ; E. B.W.,ofN.H.; G.S., of N. Y.