384 Miscellanies. 



" Experiment 1. — The length of thirty bricks was placed upon a 

 fulcrum, or prop, as nearly in its centre as would admit of the project- 

 ing ends being in equilibrium : fifteen bricks were overhanging each 

 side of the prop, and after being left in that situation for a length of 

 time, it was ascertained that no sensible change had taken place in any 

 of its parts. 



" Experiment 2. — We next placed one end of the connected bricks 

 upon a firm support, and then placed heavy weights to keep that end 

 down, leaving twenty-two bricks projecting horizontally, quite unsup- 

 ported except by the tenacity of the cement ; this projection measured 

 four feet one inch ; the average weight of the bricks was five pounds 

 each. After fifteen minutes thus suspended, the extreme end appeared 

 to have descended near half an inch, but of this we were not quite cer- 

 tain : no further change was at all perceptible. 



" Experiment 3. — This experiment was both unintentional and un- 

 satisfactory ; the workmen in removing the bricks to rest each end 

 upon a prop, that we might place weights upon its unsupported mid- 

 dle, let one of the ends fall vvith its full force upon the ground, while the 

 other end remained supported : a fracture was the consequence, but it 

 was a brick that broke and not the cement. 



Experiment 4. — Ten bricks in length were supported at each end, 

 and the weight of 150 kilograms, upwards of 300 pounds, was placed 

 upon the middle, and was allowed to remain fifteen minutes without 

 undergoing the least change ; additional weights were then added till 

 they amounted to 303 kilograms, or upwards of 606 pounds, and af- 

 ter being exposed to this weight for ten minutes it broke at the mid- 

 dle brick; but, as in the third experiment, it was the brick, and not 

 the cement, that had given way." pp. 9, 10. 



After quoting an instance or two of the use of this material as a 

 pavement, we must close our notice, and refer those who wish further 



The following are the prices at which Yorkshire stone-paving can now be ob- 

 tained in the metropolis. 



Tooled. Rubbed, 

 s. d. s. d. 

 Three inch paving, per foot superficial ... 090 11^ 



Four inch - - ditto . . - . 1 1 2^ 



The above are the prices of the small sized flag-stones ; but where larger stones 

 are required, such as are now employed for paving the bettermost streets, the York- 

 shire landings must be used, the prices of which are as follows : 



Four inch, per foot superficial 

 Five inch ditto 



Six inch ditto 



