2,004." Account of Experiments made 
a similar case of 4 inch bars, gives the ratio as the cubes, as was 
anticipated. 
In the horizontal castings of different lengths, the balance is 
in favour of the increased lengths; but in the vertical castings, it 
is the reverse. In neither is there any apparent ratio. In the 
horizontal castings at 6 inches from the bearing, there is a visi- 
ble increase, but not so great as when close to the bearing. 
June 4, 1817. Miscellaneous Experiments on the Crush of one 
No. cubic Inch. lbs. avoirdupoise. 
96 - Elm ~ 5. Mie fs 1284 
97 American pine afd Birks =i 1606 
98 White deal .. 6 Jie aie 1928 
99 English oak, mean of two trials .. te 3860 
100 Ditto, of 5 inches long, slipped with ots 2572 
101 Ditto, of 4 inches do. .. aii A 5147* 
102 A prism of Portland stone 2 inches long... 805 
103 Ditto, statuary marble .. we fe 3216 
104 Craig Leith .. 32 ar 8 8688 
In the following experiments on stones, the pressure was com- 
municated through a kind of pyramid, the base of which restea 
on the hide leather, and that, on thestone t. The lever pressed 
upon the apex of the pyramid. Cubes of one and a half inch. 
No. Spec. gray. lbs, avoirdu. 
105 Chalk ry Hf oe ee 1127 
106 Brick of a pale red colour sy 2:085 1265 
107 Roe-stone, Gloucestershire a ma 1449 
108 Red brick, mean of two trials... 2°168 1817 
109 Yellow face baked Hammersmith paviors 3 times 2254 
110 Burnt do. mean of two trials £5 a 3243 
111 Stourbridge or fire brick ee oe 3864 
112 Derby grit, a red friable sand-stone, 2°316 7070 
113 Ditto, from another quarry aia 2°428 9776 
114 Killaly white freestone, not stratified 2423 10264 
115 Portland Bi it oh 2-428 10284 
116 Craig Leith, white freestone yy 2°452 = -:12846 
* The experiments on woods are considerably below those of other 
writers; and it appears singular that the four-inch specimen should be 
stronger than the shorter length. According to Rondelet’s experiments, to 
crush a cubic inch of oak it required from 5000 to 6000 lbs. avoirdupoise 
—- — — of fir - - from 6000 to 7000 Ibs. 
In the former the pieces were compressed t-3rd of their length; in the Jat- 
ter one-half of their length (Rondelet’s L’Art de Batir, tom. iv. p. 67.) 
Mr. Rennie has not stated the diminution of length.—TV,T. 
+ It certainly would have heen preferable td have placed a bard and rigid 
substance next the stone, in order to secure equality of pressure. —T. T. 
June 
