166 NEW YOKK STATE MUSEUM 



If the bricks are put into the kiln before they are sufficiently 

 dried, or if they are heated too quickly, they are liable to crack. 



In the case of coal, grates have to be put in a few inches above 

 the level of the floor, and for oil, burners are needed. 



After a kiln of bricks has been burned the ends of the arch 

 bricks are often black, caused by the particles of dust and carbon 

 which have been carried upward sticking to the brick when they 

 were in a soft condition, due to the high degree of heat. 



As to the action of the coal dust in the brick. At first 

 while tlje brick contains water, there is no access for the air to 

 the particles of coal. However, as the firing proceeds, the water 

 is driven off leaving the brick porous, allowing the air to enter for 

 the combustion of the coal. Particles of lime and lumps of clay 

 cause a splitting of the brick. Insufficiently burnt bricks are 

 called "pale" and sell for $3.75 per 1000. 



The kilns take several days to cool, and, when cool, the bricks 

 are put on wheelbarrows, and taken to the freight cars, or barges, 

 and then shipped to the market. If the kiln shed is not situated 

 along the dock, the barrows are put on a car, which is run down 

 a track to the scow. The time of burning is from five to seven 

 days with wood and four to five days with oil. The cost of burn- 

 ing with wood is 60 to 75 cents per 1000 brick, and with coal the 

 cost of burning is 40 to 50 cents per lOUO. Burning with wood is 

 the cheapest method as far as implements are concerned. With 

 coal there is the cost of grates and with oil there is a royalty of 

 $160 to be paid on every burner. The latter is, however, the 

 cheapest method as regards the price of fuel. The great majority 

 of the yards along the Hudson use wood, a few use coal and two 

 or three use oil. With coal and oil the heat can be better regu- 

 lated than with wood. Another important point is the amount 

 of pale brick produced. Most of the yards in I^ew York burn 

 their bricks in scove kilns. In these there is sometimes a loss of 

 as much as 50,000 to 75,000 in a clamp of 500,000 bricks, while 

 in a permanent kiln such as the Wingard or similar, the amount 

 of pale brick is said to be not over 25,000 usually. Again in 

 the case of permanent kilns, it takes no more, if not less, time to 

 set the bricks and there is less daubing to be done. Regarding 

 the amount of labor required in burning, one man is supposed to 

 tend three arches. 



