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Indiana University Studies 



6. It can be mixed dry with sand or cement, thus necessitat- 

 ing less labor. 



7. There is less danger in packing and in handling. 



With these advantages favoring it, the use of lime hj^lrate 

 cannot but develop very rapidly, and plants for the hydration 

 of lime will be a pajdng investment. Mixtures of lime hydrates 

 and Portland cement are already much used in making concrete 

 walls. It is also recommended in the production of concrete 

 building blocks, where it is claimed to improve the water-resisting 

 qualities and give a lighter shade to the blocks. 



Lime hydrate is used with kerosene and copper sulphate or 

 Paris green as a spray, and as such it is recommended as a very 

 good insecticide. 



Sand-Lime Brick. The manufacture of building bricks 

 from mixtures of sand' and lime has been carried on for a number 

 of years in regions where the soils are sandy and clays are lacking; 

 but these mortar bricks are very unsatisfactory, and the industry 

 has never reached large proportions. With the patent of Dr. W. 

 Michaelis for hardening sand-lime brick by high-pressure steam, 

 the industry of making sand-lime bricks has developed to a great 

 extent. The patent, taken out in 1881, lapsed before any great use 

 was made of it, but since 1900 a large number of plants for the 

 manufacture of sand-lime brick by this method have begun 

 operation in Germany. The first plant to operate in this country 

 Avas started at Michigan City, Ind., in 1901, and at the present 

 time about 100 plants are in operation in this country. 



Sand-lime brick, or ^'Kalksandstein" as it is called by the 

 Germans, is a mass of sand grains cemented together by a hy- 

 drated calcium silicate. The union, instead of depending on 

 the lime as a cement, depends upon the formation of this silicate 

 by the high temperature which the brick undergoes in the process 

 of manufacture. This industry is sure to grow and with it such 

 a demand for lime as to cause a rise of prices in the future. 



The Lime Industry in Southern Indiana. The reasons 

 why the lime industry has not been developed in the stone belt 

 of Southern Indiana are many. In regard to this I may quote 

 from the paper on the ^'Lime Industry in Indiana" by W. S. 

 Blatchley, in the twenty-eighth Annual Report of the Indiana De- 

 partment of Geology and Natural Resources (pp. 219-220), as 

 follows : 



