Mr. White on Calcareous Cements. 



Continuation of Experiment No. It. May 12th. 



Two wrought-iron wedges 

 were driven with sledge 

 hammers at X X, for the 

 purpose of splitting this 

 pier ; it resisted very long, 

 and when separated, it 

 was found that many 

 bricks had not taken the 

 mortar. 



The mortar was not 

 completely dry, it would 

 require another sum- 

 / mer to give it all the 

 toughness and tenacity it 

 can acquire. 

 The same wedges were afterwards driven with the same ham- 

 mers, and greater effort at A A. It resisted and repelled the 

 wedges several times, but when separated, the mortar and bricks 

 appeared to have resisted alike. 



A third attempt was made by driving the same wedges at B B, 

 when a new separation took place, exhibiting the same appearance 

 as in the first separation. 



This experiment was made in the presence of the Earl of 

 Southampton, Mr. Brunei, Lieutenant-General Sir Alexander 

 Bryce, and many others. 



Fourth Experiment, May 20, 1825. 



The adhesion of the materials being, in some measure, ascer- 

 tained by the foregoing experiments, it appeared desirable to learn 

 how far the application of weight vertically would effect them, 

 when the following trials were made at Mr. Bramah's, at Pimlico, 

 by subjecting portions of the above piers to the hydrostatic press. 



First Trial, Pier A. Roman cement. — Section one hundred and 

 ninety-six inches superficial, cracked with 4S,960 lbs., the 



