230 The Philippine Journal of Science 1919 
the regular way at the plant, however, it must have a sulphuric 
anhydride content of 1.80 per cent to insure a normal set. 
Considerable difficulty was experienced in controlling the gyp- 
sum content until many physical tests and chemical analyses 
had been made, and the limits of the sulphuric anhydride 
determined. 
The effects of exposure to air and of additions of hydrated 
lime are independent of the sulphuric anhydride content. 
Soundness is independent of the sulphuric anhydride content. 
Normal consistency is independent of sulphuric anhydride con- 
tent, but increases with the amount of hydrated lime present. 
TABLE I.—Setting time of cement ground in laboratory. 
| | | 
Sulphur- sie Sulphur- ise Sulphur- 5 Sulphur- ae 
igre | est | SGamey| “eee ['sanbe-| “tees: (eyanbe-) Mee 
Per cent.| Min. | Per‘cent.| Min. Li cent.| Min. || Per cent.| Min. 
0 0 0.71 800 1.66 830 2.79 260 
0 250 0. 96 200 1.75 160 2.79 840 
0 270 0. 96 290 1.89 220 3.00 160 
0 270 1.00 0 1.89 830 3.20 190 
0.22 80 1.20 200 2.00 120 8. 63 230 
0, 22 180 1.20 810 2.00 250 3.63 350 
0.25 170 |} - 1.48 210 2.12 220 5.00 170 
0. 46 140 1.48 320 2.12 350 9.10 140 
0. 46 - 250 1.50 | 10 2.35 OB. Hs woke ce ese ce 
0.50 170 1.50 260 2.35 $50 Heads. ce a ouite woke 
0.71 200 1.66 190 2.50 80 
bs 
TABLE II.—Setting time of cement ground in plant. 
Sulphur- | ryitig) || Sulphur-| 7.44.4) |[Sulphur-| , Sulphur-| 7 .,; |Sulphar- i 
Nanda, | #% | 'GAgeY"[ eet. | 'ganby-| Miee™! | ieanhy- | Meee" | ieanhy- | 7 
Per cent.) Min. || Per cent.| Min. || Per cent.| Min. || Percent.| Min. Per cent.| Min. 
1.35 150 1.75 20 2.04 150 2. 25 220 2.44} 180 
1.45 0 1.75] 220 2.10} 140 2.26| 130 2.50| 1380 
1.45 0 1.80 0 2.11} 100 2.27 80 2.50} 240 
1.45 0 1.82} 125 2.11} 200 2.28} 170 2.51| 190 
1.50 0 1.87} © 125 2.13} 180 2.29| 130 2.75| 240 
1.52 0 1.87| 180 2.18} 950 ae Lee ee 
1.52| 160 1.91| 101 2139! 499 S91). mts te 
1.59 0 1.92] 180 2.20! 130 oe Wet a 
1.61 0 1.95} 180 2.221 110 ta Pow 
Lert: 7.8 2.00 110 2.22 160 2.88 BO ce ca 
1.62 0 2.00} 230 2.221 160 a eee ee es 
1.65 10 2.02} 140 2.22} 200 iS) Wi mats 
1.68 0 2.02] 170 2.23} 210 20) i 
1.74 0 2.08} 200 2.25] 190 cer ee 
