G. B., of N, Y.—mdash;You will get the information for calculating the power of high pressure engines in "Bourne's Catechism of the Steam Engine." It is authority, and we can find no better book to recom mend to you at present. J. F. M.3 of Pa.—mdash;We were told authoritatively that it was anthracite that was used, but didnot pay the least attention to examine for ourselves, S. and E,, of N. Y,—mdash;Perhaps your plan for thresh ing as last submitted to us is an improvement on the one uponwhichthe application for a patent is pending, but we fail to recognize the advantage of it. A, W. D., ofN. Y.—mdash;Your plan for a gas generator is very novel, and we should think it would ope rate well, but perhaps you had better construct one and try it before going to the expense of making an application for a patent. W. E., of Boston.—mdash;We know persons who have used the burning fluid for a number of years without any accident taking place. Carefulness will do all that is required. We have received a letter from another person having a valve opening in a contra ry direction to yours to do the same thing. G. L. B., of Me.—mdash;We have received a letter from another person with a valve opening in a contrary direction from yours to do the same thing. Both camnot be right. We are obliged to you for men tioning about the water pails. H.C.j of Texas.—mdash;The inventor and patentee of the improvement mentioned in your letter of the 13th ult., is now in England, and upon his return we will endeavor to call up the subject of your enquiry. H. G., of Mich.—mdash;We read every word of your long communication. We will defer our opinion until your arrival, E, T., of 111.—mdash;There is no machine for turning spokes not patented, which works satisfactorily, that we know of. J, M. Quimby, of N. J., is owner of Blanchard's patent. J. McC.j of N. Y.—mdash;An application is now pending at the Patent Office, for a machine substantially on the same plan as yours. If you wish to attest your right to the invention, you have only to make appli cation for a patent, and the Commissioner will de clare an interference, and call for evidence to prove priority. R. 0. W. H., of Tenn.—mdash;We have handed your let ter over to a manufacturer for attention, H. B. H., of Ohio.—mdash;We have carefully examined the model of your reaping and raking machine, and | think the raking part to be new and patentable We see nothing new in the reaping arrangement. There is no objection to your taking a patent. W. D. B., of Mass.—mdash;You should always sign your name to communications addressed to this office. Your device appears to possess novelty sufficient to Warrant an application for letter* patent. You can send us a model. J. C, of R. I.—mdash;Your ideas concerning the propell-ing of a balloon are absurd. We can offer you not a word of encouragement. C. E, Bacon, of Buffalo, N. Y.—mdash;Your explanation is satisfactory, and we should have so stated before, but the matter was overlooked, amid the hurry ef our business. T. S. M., of Pa.—mdash;We have the same opinion in re gard to the patentability of the lightning conductor and insulators, that we did before receiving your last letter. W. D. W., of Raleigh.—mdash;The fast of your having paid us30 was overlooked at the time you were last written to, Your case is properly entered upon our Patent Office record book, and will receive attention in its turn. You will have but25 more to remit. J. V. D., of Va,—mdash;We are sorry in not being able to furnish you with the back numbers of the present volume, but you are in no worse condition than hundreds of others who have been disappoint ed in like manner. The article on gun cotton will probably be published. E. H., of Conn.—mdash;So far as we are able to judge of your improvements on the steam engine from such a description as you give, we think itis new. A. P, of Me,—mdash;There have been many car coup lings patented which purport to obviate the evil you propose to remedy, but you may have a different plan from any of the others for producing the re sult. J. D. A., of 0.—mdash;Your diagram presents a well-known invention. Br. Wright, of Calaf ornia.—mdash;Suitable engravings of your machine for separating extraneous matter from gold, would cost you25, which amount we would thank you to remit. E. Van C, of Pa.—mdash;Your new model has Taeen re ceived and forwarded to the Patent Office. W. T. W., of Tenn.—mdash;The principle is the same in all hydraulic rams, and who makes the best we are unable to state. There is no doubt but that either of the parties will sell you a good. mill. J. M. D., of N. Y.—mdash;Your model has been received and the engravings will be executed and published in a few weeks. Money received on account of Patent Office busi ness for the week ending Saturday, Feb. 5 : C. V. D. H., of N. Y.,10 ; E. J. — J. W. B,, of N. Y.,0, E, M., of N. Y.,30; T. R., of N. Y.> $30; D. W.K., of Va.,7 ; J. P., of -.,25; J. McM., of Ky.,10; W. R, of Mass ,25; W. P., of Mo.,,50 : C. L. O., of N, Y.,30. Specifications and drawings belonging to parties with the following initials have been forwarded to the Patent Office during the week ending Saturday, Feb. 5 : D. W. K., ofVa.j W. E., of Mass,,- 0. L. O., of N. Y