Absolute waterproofing of textile materials is obtained by applying to their surface a thin layer of rubber. The first experiments were made in France by Beason in 1793; they were improved upon and perfected successively by Mackintosh and Hancock of Glasgow, Scottby Buttire and Guibal in France and by Good yyeeaarr the United States. As in the case of lbscuduin with road surfaces, the successful efforts of Mackintosh perpetuated his name in connection with india rubber waterproof gar ments. The material is prepared by spreading on the surface a semi-Nu:1 layer of rubber dissolved in benzol then submitting it to the action of heat to evaporate the solvent Car bon disulphide first employed to dissolve the rubber, was replaced by a mixture of bertzol or coal naphtha and essence of turpentine and later by benzol which alone is now used In the treatnsent of cotton and linen cloth a small proportion of sulphur is generally added. A thin layer of this rubber solution is spread on the fabric by special machinery, after which the cloth is doubled, pressed and finished in calendars, the waterproof layer being thus in the centre of the finished material. (See Rua ant MA MY/AC/VR[3. ) The offensive odor of waterproofed rubber garments may be remedied by treating than with aromatized vapors or by ‘ppng them in concentrated infusions of ver rain root, of orris root, of lavender, of camo mile, etc. Ammoniacal vapor and sulphurous and can also be successfully utilized to relieve rubbered materials of their penetrating odor. The application of rubber is made on dyed ma tenal in thread or in piece. The use of paraffrne as an impervious agent allows the tissue to be dyed after being waterproofed. Pamirs:Bed tis sues do not absorb water, which assumes a spheroidal shape and slides off the surface. chief objection to paraffine lies in the fact that it is exceedingly brittle at low tures and melts readily with ordinary summer beat. Woolen tissue, well cleaned by passing of light and tepid bath of carbonate ca and man are dried, then steeped in a mignon of paraffin in petroleum ether, 60 or 100 grammes to the quart. They are afterward passed through roller pressers, dried in the open air, and sent to the dyeing vats.
As already pointed out waterproof rub bered textiles are not only impervious to water, but also to air and numerous other methods and processes have been introduced to pro dace fabrics which, white resisting rain, do not altogether obstruct ventilation The con secutive dipping of cloths, as already explained, in soap and alum solutions or in gelatine and pll solutions or in a solution of acetate of leeaadd and then in a solution of alumina, are re sorted to with more or less success. Algin, ob tained from seaweed, has been strongly recom mended for the same purpose. One of the most modern processes consists in treating the fibres in the solution before they are manufac tured into textiles and the fabric thus pro duced, while rain-resisting, offers the same ventilation as ordinary materials. oFibre-mail,* as it is called commercially, is described as a clear, colorless substance held in solution for the purpose of treating silks, woolens, cottons, feathers, paper and other materials, so as to render them water-repellent and proof against dampness, mildew and moths. The value of the process is further stated to be by no means limited to the water-repellent qualities given to the goods treated. The application of the solution leaves a coating upon each separate fibre which, by the action of heat, is cured or vulcanized upon and into the fibre, strength ening it and leaving it impervious and elastic.
Among other advantages cited are the prop erties of giving weight and body to the finer textile fabrics, and by this means, where de sirable, economizing material, the quality of the goods being greatly improved and never detenorated; the process also gives lustre and finish to fabrics, being especially valuable for silks, alpacas, etc.; gives elasticity and tough ness to the fibres, preventing cracking and breaking qualities valuable for felt hats, silks, etc.; deepens and fastens the colors in dyed goods; resists stains and spots in the lighter and more delicate goods; prevents woods from swelling and warping; preserves painted sur faces; and prevents polishec•or metal surfaces from rusting.
is also successfully applied to leather and leather goods. Many compositions, some of than patented, have been long employed, for rendenng leather water proof by filling up the minute pores. Four or five may be briefly described as examples of the whole. Boiled linseed oil, mutton-suet, yellow beeswax, and common resin are melted to gether over a slow fire and applied while hot to the leather, which is itself to be made warm. Linseed oil, resin, white vitriol, spirit of turpen tine and white oak sawdust are the materials of another composition. Yellow beeswax, Bur gundy pitch, turpentine and linseed oil consti tute a third. A fourth plan consists in apply*. ing to the leather a hot mixture of two parts tallow with one part resin. Another is to first apply a coating of tallow to the leather with a second coating of one part copaiha balsam with two of naphtha. Caoutchouc, boiled for two hours in linseed or neat's-foot oil is also said to be effective.
Structures.— Paint and silica compounds, oils, varnishes and gums have long been no perimented with for the preservation of build ings by waterproofing. The Sylvester process has long been in vogue for stone, brick and cement surfaces. It consists of alternately applying hot washes of soap and alum. Coat ing buildings with linseed oil has been a favor ite method as affording some degree of pro tection against the deteriorating action of the elements. But linseed od alone or mixed with colors, varnishes and gums has never proved wholly efficient to prevent the disintegration of stone, the weather staining of brickwork. the crumbling of mortar joints and the efflorescence of soluble salts, contairsed to a greater or less degree in all bricks, cement and some varieties of stone; this is owing to the protective ma terials in themselves being subject both to chemical changes when exposed for a compara tively short time to the weather. When lin seed oil alone is used, should there be any lime or alkaline salts in the wall, these immediately saponify the oil and render it useless as water proofing. The oil soon dries out and leaves a spotted or mottled surface. Paint is often seen peeling off from the mortar joints of a building and from the brick work as well, owing to the same cause, the caustic alkaline properties of the salts of lime saponifying the linseed oil in the paint. Among scores of pro prietary secret formulas there are some that are indisputably good and are thoroughly guaranteed by their makers. It is the custom of some architects to call for these applications in specifications.