CLAYS OF NEW YOKE 



Y51 



together in tlie same kiln, show tliat end-cut bricks possess a de^ 

 cided superiority over side^cut bricks, and also show the marked 

 advantage of repressing end-cut and the disadvantage of repress- 

 ing side^cut bricks. 



Rattling tests made by Prof. Edward Orton jr oa paving bricks 



END'-CUT BKICKS 



Loss in weight at the end Average 



Description , ^^- , ^lodulus 



1003 revolu- 3003 revolu- ^, °tiir,- 



tions tions rupture 



Per cent Per cent Pounds 



Eepressed 18.23 26. 6Y 2 525 



Plain 21.05 28.48 2 425 



Average of both 19.54 27.00 2 463 



SIDE-CUT BKICKS 



Eepressed 26 . 51 35 .30' 2 34Y 



Plain 22. Y3 31.42 2 346 



Average of both 24.43 32 . 90 2 347 



DEY PRESSED BRICKS 



Coarse 19.40 25.20 2 507 



Medium 23.80 28.26 2 740 



Pine 20.07 29.71 2 687 



Average of all 21 . 09 27 . 72 2 644 



As regards the crushing test, experiments given below show 

 that, even with the same material, a wide range of results is ob- 

 tained, depending on the method of preparing the surface. 



Prof. I. O. Baker prepared a number as follows : 



1 Grinding as nearly flat as possible on convex side of emery 

 stone and crushing between self-adjusting, parallel cast iron plates. 



2 Removing the irregularities of surface and crushing between 

 blotting paper. 



