336 Mr. White's Design for the Neic London Bridge, 



loaded, when it supported four hundred weight, and broke 

 under four hundred wei<^ht and a half 



The cement of the third pier (C) was composed of three 

 parts pozzolano and one part stone-lime, ground and fresh. 

 This pier broke in turning it round, and the fragment was 

 laid by for further experiments. 



In the fourth pier (D) it was composed of three parts pure 

 sharp sand, and one part stone-lime. This jjier broke into 

 three pieces on attempting to lay it on the supports. 



In the fifth and sixth piers (EF), it was composed of three 

 parts sharp washed sand, and one part chalk-lime; they 

 crumbled to pieces on attempting to place them. 



The seventh pier (G) had of Atkinson's Roman cement one 

 part, pure sand one part. 



Weights being carefully and successively applied at A, half- 

 hundred at a time; it supported five hundred weight, and 

 broke under five hundred weight and a half at B. On exami- 

 ning the separated parts, it was evident that the mortar had 

 not equally adhered to every brick. 



The longest end being tried in the same way as in the first 

 experiment, viz. 



It was left nearly half an hour with one ton weight at A, and 

 broke in consequence of a shock it experienced by the break- 

 ing of the pier subjected to the next experiment. 



In the eighth pier(H)the cement was composed of four parts 

 pozzolano, and one part air-slaked stone-lime. This broke in 

 laying down. A second experiment was made as in the pre- 

 ceding 



