738 
PROCEEDINGS OF SECTION H, 
— 
Weight, dry. 
Weight, wet. 
j Increase in weight. 
After 24 hours’ drying. 
Percentage ox 
weight. 
Weight after 
drying. 
Moisture 
evaporated. 
Moisture 
retained. 
Per cent, of 
moisture , 
retained. 
Grs. 
Grs. 
Grs. 
Grs. 
Grs. 
Grs. 
Plaster. No. 1 
6.665 
9,220 
2,555 
38-3 
8.520 
700 
1,855 
21*7 
Keen’s Cement, No. 2 
8,260 
8,690 
430 
5-2 
8,250 
440 
loss of 
10 grs. 
Portland and Sand, No. 3 ... 
8,450 
9,080 
630 
7-4 
8,590 
490 
140 
1*6 
Portland, No. 4 
0,780 
10,520 
740 
75 
10,100 
420 
320 
3-2 
After weighing on the 21st instant, the slabs were placed on end 
round a central support, and allowed to dry in the laboratory, and at 
a temperature of 70 deg. F. ; the results on the 22nd were as above. 
After 48 hours' drying. 
After 72 hours’ drying. 
Temp. 69° F. 
120 hours’ drying. 
Temp. 69° to 70° P. 
| 
5 
i ^ 
r- 
Moisture 
evaporated. 
Moisture 
retained. 
Per cent, on 
weight of 
slab. 
Weight. 
Moisture 
evaporated. 
Moisture 
retained 
Per cent, on 
weight of 
slab. 
§ 
© 
£ 
Moisture 
evaporated. | 
Moisture 
retained. 
go 
£34 
S “3 
Zj C3 » 
§3* 
P 
Grs. 
Grs. 
Grs. 
Grs. 
Grs. 
Grs. 
Grs. 
Grs. 
Grs. 
Plaster, No. 1 
8,170 
1,050 
1,505 
18-4 
7,780 
1440 
1,115 
1437 
7,730 
1,490 
1,065 
13*7 
Keen’s Cement. No. 2 
8,210 
490 
loss 50 
8,210 
480 
loss 50 
8.210 
480 
loss 50 
... 
Portland and Sand, 
8,530 
550 
80 
*93 
8,520 
560 
70 
•82 
8,530 
550 
80 
•93 
No. 3 
Portland, No. 4 
10,030 
490 
250 
2 5 
10,000 
520 
220 
2-2 
9,990 
530 
210 
214 
The experiment was repeated with a fresh set of slabs. They were 
placed in a pan of rain-water on 21st October at 10*30 a.m., removed 
on 22nd October at 10*30 a.m —i.e., immersed for twenty-four hours, 
removed from water, stood ou end for ten minutes, wiped with cloth, 
and weighed. b 
These slabs, like the former, were wholly immersed and lam flat 
in the water. In this and the previous experiment, the Keen’s 
cement rendered the water milky and yielded a deposit, and its surface 
appeared to have been slightly acted upon by solution ; this is also 
shown by the loss in weight which the slab sustained. The others 
also probably lost something by solution, so that the increased weight 
is, in all cases, the difference between the loss by solution and the 
increase by retention of water. Keen’s cement, after being wetted and 
dried, became notably loose and friable on the surface. 
— 
Weight, dry. 
Per cent. 
After 24 hours’ drying. 
+3 
O) 
£ 
.1? 
”8 
if 
© 
0 
1 
© 
fcj 
p 
■2 
43 
6 C 
© 
£ 
B g 
.2 o 
O o- 
<r£ C3 
© 
© ■ 
Sh 'D 
S © 
£ o 
4§ ‘S 
£ © 
a 
© 
© 
1 
Plaster, No. 1 ... 
Keen’s Cement, No. 2 
Portland and Sand, No. 3 
Portland, No. 4 
Grs. 
6,540 
8,110 
8,300 
9,830 
Grs. 
9,040 
8,510 
9,100 
10,700 
Grs. 
2,500 
400 
710 
870 
38*2 
4-9 
8*4 
8'8 
Grs. 
8,670 
8,130 
8,710 
10,330 
Grs. 
370 
380 
390 
370 
Grs. 
2,130 
20 
320 
500 
24-5 
•25 
3*7 
4*8 
