_From the London Mechanics’ Magazine, Vol. LI._ SIR:—We are reminded weekly by the advertisement in your Number, that gutta-percha “must be regarded as one of the blessings of a gracious Providence.” Doubtless this, as well as every other natural production, should be so regarded, although in the state in which it is left by Providence it would be of little use were it not for the additional blessings of ingenious-minded men, (as the Hancocks and others) by whose skill the crude gifts of Providence are manipulated and presented to our acceptance in a thousand beautiful and highly useful forms. As weather-proof, and consequently _health-preserving soles_ for boots and shoes, gutta-percha most assuredly stands unrivalled. The application of this material to _heels_ has not hitherto been equally successful, from its being unequal to withstand the vast amount of wear and tear, to which this part of our understanding is subjected, one consequence of which is liability to spread, and become worn and ragged on its edges. For this defect, however, an efficient remedy has been provided in the compound heel tips, invented by Mr. B. Tyler, of Sheffield, and manufactured under Messrs. Hancock & Co.’s patent. The frame or border of this improved steel tip consists of a rim of cast iron or steel, furnished with tangs or projections. This frame is filled up with a tough compound of gutta-percha and cork, which encloses the tangs. The heel thus formed, requires no nailing to affix it to the boot or shoe, a coating of solution being sufficient for that purpose. Thus arranged, the metal and gutta-percha mutually aid and support each other; no spreading can take place, nor can the edges become worn or ragged. These tips never become loose, neither are they liable to become slippery. Having worn them for more than two years, I can with confidence assert them to be the best contrivance extant for the purpose. * * * I am, Sir, yours &c. WILLIAM BADDELEY, _29 Alfred Street, Islington_. EDWARD JOHN PAINE, Chancery Lane, London. For improvements in marine vessels, in apparatus for the preservation of human life, and moulding, joining and finishing hollow and solid figures, composed wholly or in part of a certain gum, or a combination of a certain gum; also for improvements in dissolving the aforesaid gums, and in apparatus or machinery to be used for the purposes above mentioned. Patent dated June 7, 1849. * * * * * A WATER PROOF VARNISH.—Mix together 1 lb. gutta-percha, 3 oz. gum opal, ½ lb. linseed oil, 8 oz. sugar of lead, 2 lbs. spirits of turpentine. Place the mixture in a tincture press, the cylinder of which is heated by a sand bath, and the produce is the varnish required.