The Birmingham age-herald., 1924-11-27
But wherever concrete is mixed, slag, if available, is highly recommended.

But wherever concrete is mixed, slag, if available, is highly recommended. Blast furnace slag has most inter- esting history. It is not the intention of the writer to present in this article it's complete history, only some of the high points in connection with the de- velopment of what is now an estab- lished industry in Birmingham.
 Blast furnace slag, up until 1908, was considered only as refuse from blast furnaces. It had no commercial value other than its use as railroad track ballast, the railroads taking the slag for the hauling.
 Carnegie's Discovery.
 with this slag by using it in concrete 1 introduced slag to the trade. In 1911 recognized as high-grade aggregate for concrete.
 From tests made by Prof. Curtis s. Myers, reported in Enineering News, vol. 80, No. 20, page 956, according to G. A. Mattison, president of the Wood stock Slag corporation, is l7 per cent stronger than concrete made with peb bles on 12-4 mix; weight per cubic yard of slag concrete is Is per cent less than gravel concrete; bond strength 15 per cent higher than gravel concrete. 1-2-4 mix; transverse beams of slag 42 per cent stronger than iii concrete made with gravel, 1-24 mix, and it is further claimed that slag concrete resists shock more successfully than does pebble,s or crushed stone concrete.
 "Slag weighs 80 pounds per cubic foot as against 100 pounds for stone and 100 pounds for gravel. Chemical constitu- ents of slag are sslicia, 3S per cent lime, 42 per cent; magnesia, per cent 1; aiumina, Il per cent, and sulphur, 1 per cent.
 Physical characteristics of slag are toughness, angularity and porocity which, incorporated in sand and cement mortar make an inflexible bond. Its recognized value as an aggregate in all classes has given it first rank in the concrete world.
 'By reason of the weight per cubic yard slag can be transported by rail to distances carrying high freight rate ! III competition with gravel and stone" NluO U1 OAdSs
 The Woodstock Slag corporation is handling the entire slag output of the Woodward Iron company at its Wood ward and Vanderbilt plants. In order to find a market foT the large tonnage offered this slag isS being shipped to points in Alabama, the Carolinas, Geor- gia, Florida, Mississippi, Louisiana and Tennessee. It being used on roads as we'll as in construction of bridges and buildings. Slag is being or has been Used in concrete work on many struc- lures in Birmingham, including the Southern Railway Finley yard shops. City auditorium, Jackson office build ing, Frisco railroad shops, Woodlawn Ligh school. Phillips high school, all employing Woodstock slag as the course aggregate in the concrete.
 One of the biggest orders recently placed with the Woodstock Slag corpo- ration was for slag used in the concrete Highway from the Talladega county line to Piedmont, Ala, distance of twenty five miles, or 60.000 cubic yards.
 The Woodstock Slag corporation headquarters are in the Age-Herald building. Birmingham has warmly welcomed the corporation, the function of which is to employ labor and con vert a once refuse,' even despised prod uct, into high grade building material, to say nothing of the heavy slag ton mage supplied to railroads. The com pany is served by nine railroads, which connect very ramifying territroy.