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acetate acid added alcohol allowed alum applied bath becomes bleached blue boiling brush carbonate cement cent chloride clean clear coat cold colour consists containing cool copper covered dilute dissolved distilled dried effect employed evaporate extract filter fine fire fresh give glass glue glycerine green ground heat iron lead light lime liquid liquor mass material matter means metal method minutes mixed mixture obtained ordinary oxide paint passed paste pieces pint placed potash powder precipitate prepared prevent printing produced proportion pure quantity remain removed salt separate side skins soap soda soft solution spirit stain steam stirred strong substances sufficient sugar sulphate sulphuric acid surface taken temperature thick thin tion treated turns varnish vessel warm washed whole wood yellow
Σελίδα 90 - It sometimes happens, that jewellers, in letting precious stones, break oft' pieces by accident; in this case they join them so that it cannot easily be seen, with gum mastic, the stone being previously made hot enough to melt it. By the same medium cameos of white enamel or coloured glass are often joined to a real stone as a ground, to produce the appearance of an onyx. Mastic is likewise used to cement false backs or doublets to stones, to alter their hue.
Σελίδα 261 - To every quart of this add 10 to 15 drops of a saturated solution of indigo, completely neutral. After applying this dye to the wood, rub the latter with a saturated and filtered solution of verdigris in hot concentrated acetic acid, and repeat the operation until a black of the desired intensity is obtained. Oak thus stained is said to be a close as well as handsome imitation of ebony.
Σελίδα 18 - Place in a bottle with the chloroform ; mix well by frequently repeated brisk agitation, and pour the mixed liquids into a funnel furnished with a glass stopcock. When the chloroform has subsided, draw it off by the stopcock, and distil it on a water-bath from a retort connected with a condenser. Dissolve the residue in warm rectified spirit; digest the solution with a little animal charcoal ; filter, evaporate, and cool until colourless crystals are obtained.
Σελίδα 255 - ... pound of powdered Spanish whiting and a pound of clear glue dissolved in warm water ; mix these well together and let the mixture stand for several days. Keep the wash thus prepared in a kettle or portable furnace and when used put it on as hot as possible with painter's or whitewash brushes.
Σελίδα 458 - ¡na wooden tank, put together so that no metal of any kind can come in contact with the solution. 1 Ib. corrosive sublimate to 10 gal. water is used when a maximum strength is required, and 1 Ib. to 15 gal. when a minimum, according to the porosity of the timber ; with the latter proportion, 1 J Ib.
Σελίδα 94 - If the glue be thinned by the admixture of ether, and applied as a varnish to leather, along the seams where it is sewed together, it renders the joint or seam water-tight, and almost impossible to separate.
Σελίδα 457 - The most effective method, however, is to exhaust the air from the cylinder after the timber is inserted, then to allow the oil to flow in, and when the cylinder is full to use a force-pump, with a pressure of 150 to 200 Ib. per sq. in., until the wood has absorbed the requisite quantity of oil, as indicated by a gauge which should be fitted to the reservoir tank. The oil is usually heated by coils of pipes placed in the reservoir, through which a current of steam is passed. The quantity of creosote...
Σελίδα 83 - The glue thus made is about the consistency of molasses and is doubly as tenacious as that made with hot water. If a few bits of india-rubber, cut into scraps the size of buck-shot be added, and.
Σελίδα 395 - Tracing - paper. — (1) A German invention has for its object the rendering more or less transparent of paper used for writing or drawing, either with ink, pencil, or crayon, and also to give the paper such a surface that such writing or drawing may be completely removed by washing, without in any way injuring the paper. The object of making the paper translucent is that when used in schools the scholars can trace the copy, and thus become proficient in the formation of letters without the explanations...