W.W. F., of Ala.—We have entered all your subscribers as you requested, and such back numbers as we had on hand we sent to you, and regret at not being able to furnish you with all of them—your subscription with the others we have marked to expire at No. 26 next volume. P. H. W., of N. Y—By addressing the " American Gutta Percha Co.," this city, you will get the information you solicit of us. T. S. I, of Ohio—We are still of the opinion that your steam guage presents no patentable novelty ; still we have no objection to render our services in trying to obtain one for you, and might succeed. T. W., ofTenn.—The subject on which you make so many inquiries is too bony for us to cope with ; if you think of going into the business of bone grinding) you had better address your twenty queries to some concern that can give you practical information—we cannot. L. B. A., of Pa.—The spring carriage wheel patented by Messrs. Lamb Root) and illustrated on page 172, Vol. 6, Sci, Am., is almost identical with yours 0. M., of 111.—Your plan for ventilating railroad cars is no doubt new, but we think it has more objectionable features than Paine's, and less practical ones than almost any we have seen. T. D. S , of Ohio—Agreeable to your request, your description of the pump has been filed for future reference. 1. Z. A. W., of Phila.—We do not think it expedient to publish the engravings of your invention until we get the foreign patents secured, which will be done immediately. A. M. G., of S. C.—We have sent you a bound copy of Vol. 5 (incomplete) and credited you $1 in continuation of your subscription, A. B. B.,of N. Y.—The models of your railroad switch came duly to hand ; we find your invention has been anticipated by Wm, Colby, of Augustaj GJ-a,, who has secured his invention by an application for a patent. D. Co , Va.—Messrs Stillman, Allen Co., Novelty Works," this city, will furnish you with as good a fau blast as you will be able to find elsewhere. A. F. T , of N. Y.—On page 5, Vol. 6, Scientific American, you will find an engraving of an axle box which is identical with yours. There would be no chance for a patent should you apply. A. B., of Mich —Your inquiry is about the same as many others ire have had on the same subject. Irving's boiler is no doubt an excellent kind, but we cannot give a fall description of it until the Foreign Patents are issued, which we expect by next steamer. See notice of this invention on page 228, Vol. 8. R. H., of N. Y.—The best thing you can do for your own benefit is to get an engraving published in our columns. P. R., of 111,—We will get up engravings of your self-loading cart immediately : we had forgotten you. There has been no examination of your case yet. R. S i of Ind—We shipped a mortising machine to you by the Pennsylvania and Ohio Transportation Line on the 27th. Money received on account of Patent Office business for theweek ending Saturday, May28 :— J. Me, of N. Y., $10; P. S-, of N. Y., $15. J. K. W. a., of Pa. $10; J. H., Jr.. Wis., $25 ; J. M., of N. J., $30 ; W. W , of R. J., $25 ; J. R. H., of Me., $36 ; J. S-, of Va., $35 j S M . of Pa., $25 ; J. B. C, of Ohio, $50 ; A. S., of N. Y., $20 ; J. N., of N. J., I $25 ; G. N , of N. Y., $20; W. S-, Jr., of Pa., $45. Specifications and drawings belonging to parties with the folio wing initials have been forwarded to the Patent Office during the week ending Saturday May 28 :— P. S., of N. Y; G. B , of N Y. ; J. K. W. P. G., of Pa.; W. W., of R I.; G. M. B., of N. Y.; A S., of N. Y.; W. S., Jr., of Pa.; J. G , of N. Y. (2 cases); J. N., of N. J.; W. S., of N. Y.; P. F. C, of Ohio ; S. M , of Pa. ; G. N., of N. Y.