TECHNOLOGY. 401 



tion in view of the revival of certain suggestions concern- 

 ing its possible utilization, and the success of certain proc- 

 esses in actual use. The following are some of the suo-crest- 

 ed uses of this material: It has been proposed to cast it, in 

 imitation of stone, directly into paving and building blocks, 

 slabs, and pipes ; or to color it before casting for making it 

 into decorative tiles and other shapes to imitate marbles and 

 other highly prized decorative stones ; to pulverize it for use 

 as cement, with lime; to granulate it, or pulverize it as a 

 material for building-sand, or as the basis of a roofing-mate- 

 rial; to produce therefrom the commoner varieties of glass; 

 and to blow it by means of a steam-jet into the condition of 

 a fine wool, to serve the general purposes of a non-conductor 

 of heat. Some of these suggestions have been tried and 

 abandoned ; others, however, have been found to give prof- 

 itable results, and are successfully practised. This is not- 

 ably the case in Germany at the Georg-Marien Hiitte at Os- 

 nabriick, where large quantities of slag are granulated and 

 made (with mortar) into excellent and very popular build- 

 ing-blocks or bricks. The yearly production at this furnace 

 alone is not less than 7,000,000 at the present time, and its 

 total production up to the close of 1876 had reached 29,- 

 500,000. 



Of still greater possible utility is the suggestion made by 

 Mr. Bashley Britton before the British Iron and Steel Insti- 

 tute to utilize this waste product for producing the cheaper 

 varieties of glass. Mr. Britton contends that while it is un- 

 fitted for the production of perfectly white glass from the 

 amount of iron which it contains yet for all glass in which 

 a tinge of color is either desired or is not detrimental and 

 this includes a large percentage of all the glass that is made 

 the slag will be found quite well adapted, the percentage 

 of iron which it contains being actually beneficial, since, 

 being capable of replacing other fluxes, it will lessen the 

 amount of alkali that would otherwise be required. Mr. 

 Britton, in his very instructive paper, goes into much detail 

 to show how glass-making can be profitably introduced in 

 many locations in connection with iron furnaces. His plan 

 is at present being tried, we understand, in one or more lo- 

 calities in England, and the practical results will be looked 

 for with great interest. 



