Briquette No.
Sec. N.
Obtained from.
Date obtained and briquette
made.
No. 8,
M. L. 71
28.7.6
8 Houses
Obtained by Mr.
Date briquette broken.
32
33
28
Ko Shing
Street
5
15
Hemmings,
21
3
19
34
17
"
**
185 (55)
Hutchings.
11.8.6 Hemmings,
"
"?
JA
>>
In presence of Messrs.
On Machino No.
No. 9.
21.7.6
Hutchings.
4.8.6
Perkins, Edwards, Heu-
mings,
3
124
24
M. L. 71
37
ラウ
99
"
Sec. N.
163
17
""
לי
כל
""
8 Houses
26 Ko Shing
"
**
Hemmings,
25
589
27
Street
"}
""
"
"J
28
225
20
20
21.66
27
"
"
35
Broke at lbs.
02 03 30
3
10
8
broken
91
1.&0.
12
99
248
9
9.66
A
Reviewing the results obtained in the foregoing table, it will be seen that in all cases when briquettes were broken by No. 1 machine the breaking strain was lower than where No. 2 was used or when broken by my own method.
The reason for this is that where a very low result was obtained such as Nos. 1, 3, 4, 5, I allege that the briquette was cracked by shrinkage before it was put into the machine.
It will be noted that where I have tested the identical mortar used in making those tests, I have obtained much higher results, because my briquettes were not damaged by shrinkage, e.g.,
No.
Result on P. IF. D. test.
L. & O. test.
1.
3.
4.
5.
4.5 lbs.
1.6 2.33
"
2
71
21.66 lbs.
18.66
18.00
28.66
27
With regard to No. 5, this mortar was prepared for the Inspector without his know- ledge, he took the sample and tested it not knowing that it contained one part of lime, one part of cement and three parts red earth; yet his official result on No. 1 machine was 2 lbs. against my 28.66 lbs. both being average of 3 briquettes.
Part of this apparent reduction of strength is due to the inaccuracy of the machine No. 1 and part to the shrinkage above referred to, which shrinkage is largely due to the excess of water in the mortar. The machine No. 2 is more correct than No. 1 and machine No. 3 may be taken as entirely satisfactory. The difference in results between this machine and mine, may be attributed to the personal effect of different operators.
I have made a number of experiments with various limes, red earths, and sand under different conditions as follows:
All briquettes were broken 14 days after making.
Experiment for Amount of Water.
No. 10. Equal parts of good shell lime and red earth with the usual quantity of water as mixed on a building tested by L. & O. method...
No. 11. Red earth only and very little water, tested by L. & 0.
method
Average of three briquettes broken by L. & O. method.
19
lbs.
25
Ibs.
Average lbs.
Page 315Page 316