G. W. J. of Miss.The non-conducting matetial generally used for co\cring steam pipe?, to retaiu thdr hent, id fultetl hair cloth wrapped spirally around them. J. R, of Ln.The first mention tbat can be found of Auybody being moved by the force of steal1l is recorded in u work called ., Sl'irit nlia sac Pneumatica," where the invention of Hero of Alcxan1rin, in 120, U. C., i* notice 1. J. P., of 'Vis.Thc method yon desClibc of elevating wutcr by means of buckets attached to an endless chain, in very old, Rnd not patentable. S. R. 01 . II.- Tile difference in the temperature of water in the day and night is 80 small that it could not affect itd weight sufficiently to account for the pllcnomenon of ibJ doing morc work at niEbt than dny. G. II., of X. C.Ouo cubic foot of gas, such 8S id used for filling balloons, will elevate iuto the nir auout one ounce weight. W. T. B., of IlLThe plnn you prop08e for propelling clmal bO:ttd is Hl1bdtantially the same U3 that adopted on SOIUC rh'crs as a means of ferriage. A rope is etletched across the rivcr, nUll grasped between two clamping wheels located on the boat. By turning one of the wheels with a crank, the bont is moved back and forth. Employing steam aa the motor instead of hand po\v('r would not give novelty to the scheme. A patent conld not be had. E. S. 0., of.-.A human body, when it sinks in the water, is ao nearly of the auienpecific gravity a8 the water, that it reqllires uut aswall disturbing force to bring it to the surface. Thii ie the reMan why cunnon are fire.d over places where persons have been drowned, ill rdcr to produce a concussion which shall literally Hshake them up." N. C. T., of Ill. Wihler a patent filling for safes ia 1 composed of pluster of. ParU and mica. The buse of mOdt fireproof compositions used in safes id plaster of Paris, Valcntine & UutIer fill their sufewitli a pntent composition of plaster of Paris and nImn comhined. Their "filling" is the best known to 11S. Alum when heated, you nrc aware, throws off a vapor, and the hcat taken up in producing this vapor, which is allowcd to cscape, id so much heat carried away from the safe. A. C. M., of Mass.* An assignee of an invention has no right to improvements made. upon the same, without the nssignment contains a covenant to that effect. The addition of the words Uor may be granted,tt after the words " to the full end of the tcrm for which said Lctters latcnt nrc," would not convey this right. A pat elltee having addigneil his riht to au invention can obtain a separate patent for any improvement he may make upon it, but he cannot l1!e nuy part of the invcntion covercd in the original patent without the as-sigueea' consent, any morc than an oubide party can ; nor I3 the assignee allowed to use the improvement without the consent of its inventor. C. F., of N. J.India rubber aud other ,oft materials bave been attached to the bottoms and corners of irunks and chests, for thc purpose of relieving the shock and injury consequent upon these parta being brought into violent contact with other objects, and your suggestion is not there10re patentable. L. W. of Del.Young ladie, are at all times interesting, but doubly must be the lovely fair one whom you describe aa having a mustache of U dark color, aoft audeilky in the extreme." Your sympathy runlS in the wrong direction. An appendage 10 graceful and die-tingue should, by aU means, be preserved and culti vated ; but perhaps your seutle friend will think differcnUy. If she wHll procure a pair of those delicate little tweczcra that arc sohl in the shops, she can very readily root out the offending hairs without the least injury to her Ivory Bkin. L. B. P.t of Ohio.-The lUea of a machine forraking and binding grain from the swath is not new. nut perhallS in the details of your construction Eome novelty exista. Working the seeding parts of " planter by the foot or by a trendle is not new. J. G. C., of Va.The idea of employing a balloon or bydrogen gaa to lift the body or a vessel above the surface of the sea, while tbe paddle whee13 project down, and act as propellers upon the water, is very old. You are decIdedly behind the times. A later aud bettcr plan is to lift the vessel 80 far above the earth as to set rid of the attraction of gravitation; then hold still until the earth turns, and brings the place you desire to reach immediately beneath your maclline, Bnd then descend upon the "pot like a hawk. Tbe employment of steam, hot air. electricity, paddle wbeels and screwe will thus, you perceive, be saved. Money reech'ed at the Scientific American Office on account of Patent Office bW!ine, for tbe weekending Saturday, July 31.1838 : H. L. A. of Wi.,$30; E. L. L., of N. Y.. $.30; . M., of Mich. $30; C. & n.. of Ill. $30; J. I'. H., of Ill., $25; E. L., of Conn. $25; J. II., of N. Y.; $55; F. B.ofConn.,$25; S. S. T. of Ind. $30; E. M., of , $25- & D., of N. Y. $'iO; J. n. C., of N. Y., $155 ; A. F. B., of Wis., $25; W. W. L of Ohio, $400 ; R. & Bros., of Conn., $25 ; A. D. B. of N. Y., $55 ; T. &B.,of N. Y., $IOO; W. A. H. of N. Y. $25; T. S. R. of N. Y. $2Q; J. C. DeW. ofN. J..,$27; E.C.,of Mafe, $* ; J. n.. of N. Y., $30 ; C. II. K., of Me.. $15 ; S. Y., of MILsa, $30; J. S., of Ohio, $25 ; I. D., of Conn., $131); D. W. T., of Ill., $30; T. C. A. of Ohio, $30; P. &11, of N. Y.,$25; W. C, of Mass.,$250; W. S., of Mo. $25; A. F. & J. H. A of Conn., $25; ,T. H. T., of N. Y.,$55; W. P., of DeL, $30; T. H. IC, of Ga., $30. Specifications and drawings belonging to parties witb E the following initials have been forwarded to tbe Pat- Jj ent Office during the week ending Saturday, July / 31.1858: /L G. M. P., of Mass. ; H. L. A., of Wifl. ; R. & Bros. jSof Conn. ; J. r. II., of m. ; R. J. M., of N. Y. ; E. L.. f Conn. ; J. H. C, of N. Y. ; E. M. of N. Y. ; J. S. of Ohio; J. M. S.,of Cal.; F.n.,of Conn., P. & 1I., of N. Y. ; J. C. DeW., of N. J.; W. II. Van G. of N. J. ; A. F. B., of Wi.,. ; C. II. R.. of )[e. ; A. F. & J. II. A. of Conn. ; W. S., of [o.; K. &D.,of N. Y.
This article was originally published with the title "Correspondents" in Scientific American 13, 48, 383 (August 1858)