234 ANNUAL REPORT, 
SOs, (ACAD NEO. 8 (2x'CaO)) SnO),(2ZCaAO NO? (27a) SiO, (2Ca 
O)ANGO. = (ACA) SiO, (ACaQ) AL Or, 
. Each series again was made up of five meinbers, in which the ratio 
of clay substance to free silica, which is also expressed by the silica- 
alumina ratio, was made to vary. The following ratios were employed: 
ye MeO Al Qik Alsi : 
The compositions of these cements are tabulated as follows: 
< E o Ate by ES 
cilgsiorses anaeoa ae ess apse aatcl e S 
© aS 5. 3.3 OS BO 2 |. 1a cdoe Formula. 
z| & Bl ees ae | ee Ieee 
1 | 64.15 | 17.27 | 14.25 | 3.09 | 1.30 | 1.21 | 2.20 | (8CaO)Si0 ,(2CaO)Al,O, 
DN YAO NGS) it TO) SXO) 1) P2637 Bb] IL 0) 3 
66.23 | 20.82 S(G4b | BGBs bisa Wt Bo4al | 4b wt 
66.98 | 21.68 BAe tH DOs Tf UB BLS | He PB 
68.16 | 22.23 AO | Pot] AL ake). fb I e/ (O@) 
17.68 | 14.47 | 2.69 | 1.30 | 1.22 | 2.07 | (2.9CaO)SiO ,(2Ca0)Al,0, 
2 
65.73..| 19°88 | 10:28 2°83" | 1.34 | 193 13228 
66.19 | 20.87 | 8.62 | 2.88 | 1.35 | 2.42 | 4.11 
CON O(a B® w& 
(or) 
w 
ora) 
I) 
66.73 | 21.86 | 7.07 | 2.93 | 1.36 | 3.09 | 5.25 
22.64 |} 5.71 | 2.74 | 1.37 | 3.97 | 6.74 
rots 
S 
(oy) 
= 
or 
pis 
11 | 62.38 | 17.50 | 14.99 | 2.82 | 1.27 | 1.17 | 2.00 | (2.8CaO)SiO;,(2Ca0)A1,0,, 
12 | 64.72 | 20.42 | 10.72 | 2.81 ; 1.32 | 1.90 | 3.20 
13 | 65.50 | 21.27 | 8.85 | 2.82) 1.33 | 2.40 | 4,08 
14 | 66.35 | 22.338 | 7.11 | 2.84 | 1.35 | 3.14 | 5.33 
Ma) || (Cea HE | 274675) | DD) | PAA | Be | Ze |) O.OX 
17 | 64.35 | 20.61 | 10.82 | 2.86 | 1.31 | 1.91 | 3.24 | (2-7CaO)SiO0 ,(2CaO)A1,0, 
18 | 64.99 | 21.80] 9.01 | 2.88 | 1.32 | 2.42 | 4.11 
19 | 65.76 | 22.70 | 7.32 | 2.89 oes |) BLO: | BBW 
20 | 66.30 | 23.76 | 5.65 | 2.96 | 1.35 | 4.20 | 7.14 
The -high-lime mixtures were burnt in a crucible furnace, lined 
with magnesite, fired with gasoline gas; the low-lime cements 
were burnt in an up-draft test kiln. All of the cements were cooled 
rapidly in the air as soon as vitrified. Owing to the iron content 
it was an easy matter to-determine when vitrification had set in. No 
