S. K. &J. A. Moore, of Mount Jackson, Va., wish to correspond with bolt and nut manufacturers. J. B. M., of N. Y.—The method of affixing wooden profile letters to stone is by applying white lead, ground in oil, as it comes from the keg, to the back of the let-lers, and pressing them against the wall, to prevent the lead from losing its adhesive qualities, on account of the absorption of the oil by the stone. Ascertain where the letter is to be placed, and form a rough outline of the letter on the stone with any oil color, and when dry apply the letter. The colorshould have gypsum as a dryer. P. S., of-----.—We think that the reason why you have been aj)le to explode kerosene is because alcohol has been mixed with it as an adulteration. Kerosene itself can scarcely be called explosive, and we have never heard of any accident resulting from its use. P. R., of N. Y.—Your theory of accounting for the fact that water exerts more power on a water wheel at nightthanin the day time, by assuming that the air is lighter, and consequently a cubic foot of water weighs more than in the daytime, Gan scarcely be correct, lor even supposing such to T)e the case, the wheel and machinery, or the resistance to the action of the water would also increase in the same proportion; so we must try and discover some other reason. C. S. G., of N. Y.—You will find articles on roofing cements on pages 286 and 294 of the present volume, Sci. AM. S. S. W., of Ky.—The best work you can get for your purpose is Dana's " Manual of Mineralogy," published in New Haven; it will give you more information than any book we know. You had better get the specimens from some friend in Louisville, where we should think plenty are to be procured. W. B. B., of 111.—If you buy the right to use a machine in a certain county, of course you cannot use it in a county that you did not purchase. B. D. J., of Pa.—Vessels and pipes lined with glass, porcelain, c, for the purposes you name, are well-known. You could not obtain a patent therefor. A. H. L., of Wis.—The rule which you have applied to calculate the horse-power of your engine is correct, except that you should have allowed 20 per cent for the difference of pressure between the boiler and the cylinder. W. H. Smith, of Newport, R. I., wishes to correspond with parties that have machinery for inserting card teeth, No. 12 or 14 wire, through two or three-ply rubber belting, 12 or 14 inches wide. W. H. S., of R. I.—The cotton is picked from the pod ia the field, leaving thebo|l on the stalk. See engraving of a cotton harvester on page 280, this volume, Sci. AM. We have concluded to give you a three-column engraving. G. W. McQ., of Tenn.—A stream of water of 64 cu-bie inches, moving at a velocity of 5 feet per second, has a nominal power of 13-1,000 of one horse-power; and the same stream, moving at a velocity of four feet per second has 1-100 of one horse-power. This is ascertained by calculating the weight af 64 cubic inches of v/ater, which is equal to a little less than \%lbs., (accurately equal to 1.459 lbs.) multiplying this by the velocity in feet per second, and dividing by 550. It is impossible to use a stream of water having only five feet velocity on a fall of 3)5 feet, or on a fall of 18 feet. A heavy body falling over a hight of 36 feet acquires a velocity of 48 feet, and it accomplished this in \% seconds; the same body falling over 18 feet acquires a velocity of 34 feet in little over one second. It wlil always have a bad :ffect if the water is brought in a chute on the wheel, as the percussion or the impact thus effected causes a re-acUon which retards the motion of the wheel. To lay down the rules for the construction of a water wheel for a given quantity of water at a given fall would take more space than we can spare in one number of our paper. Numbers of books have been written ou this eub-ject We would only remark that for high falls over 30 feet a turbine wheel is always the best. W.H. T.,ofC. W.—Butter is produced by the oxygen of the air being brought into contact with tbe fatty substance of the cream. The shortest way to makebutteris not tie best. The cream should be kept in an airy apartment, and when churning the cream should be at a temperature of 60 degrees. A. M. S., of Mass.—We have carefully examined your sketch of the sash-fastening, and are sorry to state that it does not contain any patentable features. Substantially the same device has frequently passed through our office. C. M., of Kansas.—We have examined the rough sketch of your plan for a method of steering vessels, and cannot discover anything of a patentable character in any of its parts. We would not, therefore, adviso you to prosecute it any further. J. P. &Co., of Pa.—The best method you can adopt to consume your smoke is to request the stoker, every time he " fires up,'' to push the red-hot fuel to the back of the grate, and then to place the new fuel on the front, give the bars a rake, and never by any chance throw damp fine coal or tan on the top of hot and burning material. This, we suspect, is the cause of your smoke. N. H., of Ohio.—We have examined your sketch of feed gear for muley saw, and are of opinion that it is not patentable. We have seen substantially similar devices. S. E., of 111.—We have carefully examined your model of a clothes' washing machine, and would state so much has been done in this line that at this late day it is extremely difficult to say anything regarding its L patentability. We have seen the same idea carried — out in various ways. We would suggest that you should / have a preliminary examination made by us at Wash- X* i:iton. In such cases, wJwre so many patents exist, it g isjialways advisable. Money received at the Scientific American Office on account of Patent Office business, for the week ending Saturday, July 17,158 :— T. H., of Ohio. $30; J. L. F., of Texas, $65; C. W. &W. W. M., of 111., $25; T. F., of Mo., $60; H. &M., of Pa., $10; W. H. Van G., of N. J., $20 ; S. D. C, of Wis., $250; A. S., of 111., $35; T. E. S., of Pa., $25; A. F. &J. H. A., of Conn., $30; E. G. A., of Conn., $25; J. P., of Ohio, $25; R. M. T., of Mich., $30; H. C. S., of Ohio, $5; P. &H., of N., Y., $25; F. K, of N. Y, $25; J. B., of N. Y., $15; J. W. H., of R. I., $73; J. A. T., of Ohio, $25; R. M., of N. YM $30; A. F., of Ohio, $20; A. P., of Tenn., $30; E. G. G., of N. Y., $25; W. A. M., of Minn. Ter., $30; W. M. W., of N. Y., $50; D. C. R., of 111., $27; G. W., of N. Y, $30; A. J. D., of Cal.,$25; E. W. K, of 111, $25; N. T. S., of Mass., $55; W. N. T., of Iowa, $30; H. &II., of N. Y., $25; J. R. F. ,of Ohio, $25; A. T., of N. J., $25; J. B. B., of Conn., $33; F. B., of Conn., $30; T. S., of Pa., $100; W. N. W. Jr., of Ohio, $25; J. M., of Miss., $20; J. O., of N. Y., $250i J. II. W., of Wis., $25; F. G., of L. I., $32; B. O., of Ohio, $30; P. R. L., of S. C, $30; A. M. H., of N. Y-, $25; T. R. R., of Ohio, $25; E. S., of La., $35; J. D. F., of Conn., $20; O. H. S. B.. of Ind., $30; M. M. of L. I.. $25; O. S., of L. I., $25; W. W., of Conn. $56. Specifications and dra trings belonging to parties with the following initials have been forwarded to the Patent Office during the week ending Saturday, July 17,1858 :— E. G. G.. of N. Y.; W. N. W. Jr., of Ohio; F. G., ofL. I.; D. C. R., of 111.; F. K., of N. Y.; F. B..of Vt; H. C. F., of Pa.; W. M. W., of N. Y,; J. B., ot N. Y.j E. W. K, of 111.; J. D. F., of Conn.; W. W., of Conn' C. W. &W. W. M., of 111.; T. F.. of Mo.; A. G. D., of Conn., F. &B., of Wis.; A. J., of N. J,; A. J. D of Cal.; O. S., of L. I.; J. P., of Ohio; T. B. B., of Conn.; H. &H., of N. Y.; K. &F., of Texas; J. W. H., of R. I.; A. FM of Ohio; M. M., of L. L; J. H. W., of Wis.: T. E. T., of Pa.; E. G. A., of Conn.; A. M. H., of N." Y.; E. S., of La ; T. R. R., of Ohio; G. C, of N. Y H. C. S., of Ohio; J. R. F., of Ohio. Literary Notices BIBLIQTITECA SACEA. W. F7l—raper, Andover, Mass. This most valuable periodical for the present month nj?fl5 Tmb,er ? Ytics which show the powefof "ThJU,lto their full advantage, the beat being The Greek Church," by Rev. J. M. Manning, of Boston, and " Waa Peter in Rome and Bishop oi the SWif %"??".,tr.an8latedl"rom the GermVof El-lendorl, by E. Goodrich Smith. CHARLESTON MEDICAL JOURNAL AND REVIEW. J. Dickson Burns, M. D., Charleston, S. -C. The bimonthly number for July contains a portrait of Prof. Meigs, of Philadelphia, and many articles of interest not only to the medical world but to the general public also. There is a candor, openness and honesty about this journal which pleases ua much, and in our opinion it ia one of the first publications of its kind in the world. TUB CINCTNNATUS. Farmers' College, College Hill, Ohio, This periodical, designed to promote scientific agriculture and pomology, and also to inculcate a higher taste in science and art among agriculturists, is improving rapidly ; and as the subscription is very low we heartily recommend it. NEW ORLEANS MEDICAL NEWS. Edited bv D. Warren Brickell, M. D., and E. D. Fenner, M. D. The July number of this valuable periodical contains much matter which i3 of interest to the faculty, and all the medicalnewsthat is worth hearing in the South. To our Subscribers RECEIPTS—When money is paid at the office for sul) scriptions, a receipt for it will always be given; but when subscribers remit their money by mail, they may consider the arrival of the first paper a bonafide acknowledgment of the receipt of their funds. The Post Office law does not allow publishers to enclose receipts in the paper. PATENT CLAIMS—Persons desiring the claim of any invention which has been patented within fourteen years, can obtain a copy by addressing a letter to this office, stating the name of the patentee, and date of patent when known, and enclosing $1 as fee for copying.