CLAYS OF NEW YOEK Y55 



xmiform results for any given make of brick, and while it is dis- 

 tinctly more sensitive in indicating tlie softer grades of brick, tbe 

 device as now manufactured embodies objectionable features wbicli 

 tbe committee think can be remedied. As between the present 

 standard ]Sr. B. M. A. test described above, and the Talbot standard 

 test, the committee found that the latter is much more sensitive in 

 selecting the soft brick, and also gives more uniform results than 

 the present standard. 



The committee therefore recommended the abandoning of the 

 present 'N. B. M. A. test, and the adopting of the T'albot standard 

 test, which is to be carried out as follows: 



1 All brick shall be thoroughly dried before testing in the rattler. 



2 The present standard rattler, 28 inches in diameter, and 20 

 inches long, shall be retained. It is preferably made of steel plates 

 in place of cast iron, which peels aind ultimately breaks under the 

 wearing action on the inside. The rattler shall be run not less than 

 28 nor more than 30 revolutions a minute for 1800 revolutions. 



3 The charge to be placed in the rattler shall consist of nine 

 paving blocks or 12 paving bricks together with 300 pounds of 

 shot made of ordinary machinery cast iron. This shot shall be of 

 two sizes; the larger size to weigh about 7^ pounds, and to be 2-| 

 inches square and 4^ inches long, with slightly rounded edges; the 

 smaller sizes to be cubes, 1^ inches on a side, with rounded edges. 

 Farther, the individual pieces of cast iron shall be replaced by 

 new ones when they have lost -i^of their original weight. One 

 fourth (Y5 pounds) of the short charge shall be always composed of 

 the large cast iron blocks, and three fourths (225 pounds) of the 

 small cast iron blocks. 



New YorJc paving hrich industry 



Most of the paving brick manufactured in this state are made 

 from shale. The localities are as follows. 



Coming. The Corning brick and terra cotta company manu- 

 fr.ctures a paving brick from the Chemung shales. The brick are 



