CHAPTER IV.

VULCANIZATION.

The importance of the improvements in gum-elastic for educational purposes, has been previously commented upon in previous portions of these notices, and we would now give a little additional space to some of the many purposes in this direction, which assist in filling up the almost infinite measure of the uses of vulcanized India-rubber. Much has been done to perfect them, but enough has already been accomplished to prove that the causes of education will hereafter be promoted by the use of many articles made of the vulcanized fabrics. The cheapness of some of these articles, compared with the cost of those of other materials, gives double assurance of the correctness of this view. The expensiveness of globes, for instance, which are admitted by all to be by far the best means of imparting and obtaining geographical and astronomical information, has rendered them accessible to few persons, either pupils or teachers. The adaptation and application of gum-elastic to these purposes, will bring within the reach of every youth in the commonest school, a perfect globe, at a price within their means, and maps more durable than leather or parchment, at cheaper rates than paper maps are now made when mounted on linen.

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The outline maps which we have seen, are printed upon the vulcanized India-rubber fabrics, both transparent and opaque, and also upon various articles to be used for other purposes besides maps, such as piano covers, crumb cloths, and carpets. Arrangements are being made for this manufacture, which may facilitate the method of teaching from outline maps by printing on this material, maps of the world, upon a scale large enough for “papering” the sides of an ordinary sized room of a school house, academy, public lecture room, or dwelling. The same map, when suspended at a suitable distance from the wall, with lights placed behind it, may be used as a transparency for teaching at night. A series of sectional maps printed on a scale as large as can be conveniently printed upon calenders, after the manner of calico-printing, may be cemented together, and arranged upon rollers.

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The globe has heretofore been so expensive, as to be found only in schools of the higher class. No form of map or atlas can give so correct an idea of the surface of the earth, or of the relative situation of places, as a globe. An attempt appears to have been made by Mr. Goodyear to make them of gum-elastic, soon after the discovery of the “acid gas process.” These attempts have been followed up at intervals, until the production of the present process. They are made of various sizes, and when embossed by the method described in the manufacture of hollow ware—by steam and vulcanization—they may be made to supply the present deficiency of globes for the blind.

Their utility and importance to the cause of education need not, we are sure, be insisted upon, when it is understood that any child can be furnished with a perfect globe at a price to come within ordinary means. When used they are inflated with air, and when collapsed, may be folded in so small a compass as to be no incumbrance under any circumstances. When the large sizes are filled with hydrogen they become highly ornamental and beautiful objects.