A patented preparation for automatically repairing punctures in bicycle tires consists of glycerine holding gelatinous silica or aluminum hydrate in suspension. Three volumes of glycerine are mixed with 1 volume of liquid water glass, and an acid is stirred in. The resulting jelly is diluted with 3 additional volumes of glycerine, and from 4 to 6 ounces of this fluid are placed in each tire. In case of puncture, the internal pressure of the air forces the fluid into the hole, which it closes.

To Fix Iron in Stone

Of the quickly hardening cements, lead and sulphur, the latter is popularly employed. It can be rendered still more suitable for purposes of pouring by the admixture of Portland cement, which is stirred into the molten sulphur in the ratio of 1 to 3 parts by weight. The strength of the latter is increased by this addition, since the formation of so coarse a crystalline structure as that of solidifying pure sulphur is disturbed by the powder added.

White Portland Cement

Mix together feldspar, 40-100 parts, by weight; kaolin, 100 parts; limestone, 700 parts; magnesite, 20-40 parts; and sodium chloride, 2.5-5 parts, all as pure as possible, and heat to 1430° to 1500° C. (2606° to 2732° F.), until the whole has become sintered together, and forms a nice, white cement-like mass.

Cement for Closing Cracks in Stoves

Make a putty of reduced iron (iron by hydrogen) and a solution of sodium or potassium silicate, and force it into the crack. If the crack be a very narrow one, make the iron and silicate into paste instead of putty. This material grows firmer and harder the longer the mended article is used.

Cement for Waterpipe


Mix together 11 parts, by weight, Portland cement; 4 parts, by weight, lead white; 1 part, by weight, litharge; and make to a paste with boiled oil in which 3 per cent of its weight of colophony has been dissolved.


Mix 1 part, by weight, torn-up wadding; 1 part, by weight, of quicklime, and 3 parts, by weight, of boiled oil. This cement must be used as soon as made.

Cement for Pallet Stones

Place small pieces of shellac around the stone when in position and subject it to heat. Often the lac spreads unevenly or swells up; and this, in addition to being unsightly, is apt to displace the stone. This can be avoided as follows: The pallets are

held in long sliding tongs. Take a piece of shellac, heat it and roll it into a cylinder between the fingers; again heat the extremity and draw it out into a fine thread. This thread will break off, leaving a point at the end of the lac. Now heat the tongs at a little distance from the pallets, testing the degree of heat by touching' the tongs with the shellac. When it melts easily, lightly touch the two sides of the notch with it; a very thin layer can thus be spread over them, and the pallet stone can then be placed in position and held until cold enough. The tongs will not lose the heat suddenly, so that the stone can easily be raised or lowered as required. The projecting particles of cement can be removed by a brass wire filed to an angle and forming a scraper. To cement a ruby pin, or the like, one may also use shellac dissolved in spirit, applied in the consistency of syrup, and liquefied again by means of a hot pincette, by seizing the stone with it.