G52 I^EW YORK STATE MUSEUM 



lock. The relative hardness of a limestone may affect its com- 

 mercial value in several ways. If too hard, the cost of quarrying 

 it becomes great, and it will be more difficult to bum, whereas, 

 if soft, it may tend to break up or pulverize in burning and con- 

 sequently clog up the kiln. If we must use a silicious limestone, 

 it is best to have one in which the silica is evenly distributed. 



USES or li]viesto:n'e 



Limestone is used in the industrial arts to a large extent in 

 either its raw or burned condition, and in the following pages an 

 attempt has been made to describe 1) the uses of common and 

 niagnesian limestone 2) the uses of lime, and 3) argillaceous 

 limestones or cement rock. 



Paper-making 



Much paper is now made from wood pulp, that known as sul- 

 fite pulp being a superior grade, in whose production consider- 

 able quantities of both dolomite and limestone are used. The 

 following description of its use has been kindly furnished to me 

 by T. A. Howard, of the Vermont marble co. 



The broken stone is thrown into cvlinders, 8 feet in diameter 

 and 20 to 160 feet high. When the tubes are full, fumes of 

 sulfuric acid are led into the bottom, and water allowed to trickle 

 down from the top. The stone thus becomes slowly dissolved, 

 and the liquor is drawm off into storage tanks. This solution is 

 used to ^^ cook " the wood. The latter is cut into chips one 

 or two inches long, and put in a '^ digester " holding seven or eight 

 cords of wood. The liquor is also introduced, and the mixture 

 heated by steam is under pressure for several hours. The sulfite 

 of lime or magnesia removes all the pitch and everything except 

 woody fibers, and at the same time removes all discoloration. 



Some manufacturers say that the liquor can be made faster 

 and stronger by the use of dolomite, in order to get which they 



