6o NEW YORK STATE MUSEUM 



be well adapted to its manufacture. The preparation of the soft 

 plastic clays consists first in passing them through a disintegrator 

 without water. Coal screenings, sand, and grog of crushed burned 

 brick may be added at this point. The mixture then goes to a set 

 of rolls, through a pug mill and finally to the machine, which is 

 generally a horizontal auger type, but may be a tile press. Shales 

 are usually pulverized in a dry pan, water added to the ground 

 material which then is finished in a wet pan as substitute for the 

 pug mill. Drying is performed by steam, waste-heat, or direct-heat 

 tunnels, and also in covered pallet yards. The product is burned 

 in down-draft kilns with bituminous coal for fuel. The burning 

 requires about 5 days. 



The production of fireproofing has been carried on in recent years 

 at eight plants, of which three are in Erie county and one each in 

 Monroe, Livingston, Rensselaer, Niagara and Kings counties. The 

 output has varied considerably from year to year with the activity 

 in building operations and in the last three seasons naturally has 

 shown a tendency to decline. The value for 1914 was $245,034, 

 for 1915 $177,844, for 1916 $174,786, for 1917 $140,464 and 1918 



Ii74,974- 



Paving brick. The manufacture of paving brick is one of the 

 branches of the clay-working industries that has shown evidences 

 of substantial growth in recent years, although it received a setback 

 with the outbreak of the war and consequent suspension of active 

 road building throughout the State. The first paving brick were 

 made in 1888 at Elmira. Since then plants have been erected at 

 several other localities, namely, Binghamton,' Coming, Hornell, 

 Jamestown, Newfield, Syracuse and Catskill. The maximum output 

 was recorded in 1914, when the returns showed 46,696,000 brick 

 valued at $680,226. In the following year owing to conditions 

 brought about by the war the output fell to 26,154,000 worth 

 $382,502. In 1917 it was 12,906,000 with a value of $248,506. 

 The 1918 production was 4,784,000 valued at $104,764. 



The materials most commonly employed for paving brick are 

 fire-clays, but in their absence the Devonian shales have been tested 

 out and certain occurrences found to be well adapted for the piurpose. 

 The shales belong to the Hamilton, Portage and Chemung formations 

 which outcrop in belts extending east and west across the central 

 and lower tiers of counties as far south as the Pennsylvania state 

 line. There are many places where the shales outcrop in force under 

 conditions favorable to their excavation and use, but they do not 

 all possess the necessary physical and chemical properties so that 



