Chaf. III.
ON STONE.
699
Cragleith.
Darley Dale.
Heddon.
Kenton.
Mansfield.
Specific gravity of parti-cles -
2-646
2-993
2-643
2-625
2'756
Absorbent powers, when
saturated under the ex-hausted receiver of anair-pump
0-143
0-156
0143
0-151
Disintegration—Quantityof matter disintegratedCohesive powers
0-6 grs.Ill
0-121 grs.100
10-1 grs.
56
7*9 grs.70
7-1 grs.72
As a general remark, it may be inferred that those stones which have the greatest specificgravity possess the greatest cohesive strength, absorb the least quantity of water, and disin-tegrate the least by the process which imitates the effects of weather, though we are notable to compare stones of different classes together, for while sandstones absorb the leastwater, they disintegrate more than the magnesian limestone, which absorbs a great quantityof water.
,5
e
Bulk of Waterabsorbed;2-inoh Cubesconsidered asUnity.
Cohesive Powers.
*
..
Name* of theQuarriesspecified.
■g c
fit
•&&J
Weightwell-dried inGrains.
ill
W
'Sail
= s i
?f|
|jp
£
tti
o = 2
*•55
If- a
LJg
3
IP
$¥
u •c *
25
c£
c**
Specific Gravi
of the dry Spe<
mens.
Specific Gravi
of the Solid
Particles.
lilii
*isll
i — 0 c
a ® — 0
M 0
Cragleith -Ditto
4098-7
4737*8
4695-6
4734-3
4859 0
163-4
0-080
0-6
60
ttl
Darley DaleDittoDitto
46R52
4746-2
4678-3
4737-4
4826-5
4880-0
148-2
88
100
2-230
2-666
0-163
Heddon
Ditto
Ditto
4557-1
4594-0
4553-8
4588-3
4765-10
211-2
0-104
10-1
26
56
2-229
2-565
0-156
Kenton
Ditto
Ditto
4658-4
4595-4
4647-9
4581-5
4848-5
200-6
0-099
7-9
48
70
2 045
2-706
0-244
Mansfield -Ditto
Ditto
4700 24733*5
4695-3
4719-4
4906-0
210-7
0-104
7-1
28
72
2-338
2-756
0151
Results of experiments upon cubes of 2 inches in diameter.
Results of experimentson cubes of 1 inch indiameter.
In the foregoing table the first column gives the name of the quarry where the specimenwas procured.
The second indicates the weights of the specimens in the state in which they are usuallyemployed for the purposes of building, subjected only to the atmospheric influences sincetaken from their respective quarries and worked.
The third contains the weights of the same specimens, after having been perfectly dried,by exposure in heated air for several days: their relative specific gravities are indicatedby these numbers, subject to the errors arising from differences in the sizes of the cubes,which, on account of the accuracy of the measurements, varied but little from each other;the specific gravities, however, taken by the most certain method, will be found in columns10 and 12.
The fourth exhibits the weight of one set of the above-mentioned cubes, after having beenimmersed in water for several days, so as to become completely saturated, such weightshaving been ascertained immediately after the cubes were taken out of the water, andwiped.
The fifth shows the difference of weight between the same specimen in its dried and inits saturated state, and indicates, therefore, the quantity (by weight) of water absorbed byeach stone.
The sixth shows the relative bulk of water absorbed, 8 cubic inches, or the bulk of thecube being taken as unity.
The seventh gives the quantity of disintegration of the several stones in grains, afterhaving been simultaneously subjected to Brard’s process for eight successive days; themeasures thus obtained may be considered very closely to represent the action of the atmo-sphere during successive winters on the various stones submitted to examination.
The eighth and ninth columns contain the results relating to the cohesive strength of thestones, or their resistance to pressure. These expeiiments were made at the manufactoryof Messrs. Bramah and Robinson with a 6-inch hydrostatic press, the pump of which was1 inch in diameter: according to previous trials by Messrs. Bramah and Robinson, 1 poundweight at the end of the pump lever produced a pressure on the face of the cube equal to