------------+----------+--------------------+----------+--------+----------- | | | | |Sulphate of Number | | Bacteria. | | | Alumina of Days |Turbidity.+----------+---------+ Per cent |Per cent|used Grains Represented.| |Raw Water.|Effluent.|remaining.|removed.|per Gallon. ------------+----------+----------+---------+----------+--------+----------- 6 | 0.03 | 14,037 | 6217 | 44.29 | 55.71 | 0.00 3 | 0.07 | 5,170 | 991 | 19.15 | 80.85 | 0.21 25 | 0.05 | 2,403 | 143 | 5.95 | 94.05 | 0.38 20 | 0.06 | 6,531 | 185 | 2.84 | 97.16 | 0.64 27 | 0.06 | 5,811 | 122 | 2.10 | 97.90 | 0.88 14 | 0.06 | 14,978 | 412 | 2.75 | 97.25 | 1.11 10 | 0.06 | 15,787 | 390 | 2.47 | 97.53 | 1.37 10 | 0.05 | 10,847 | 47 | 0.43 | 99.57 | 2.17 | | | | | | 14 | 0.16 | 7,525 | 256 | 3.40 | 96.60 | 0.60 17 | 0.24 | 11,310 | 208 | 1.84 | 98.16 | 0.91 15 | 0.24 | 15,441 | 262 | 1.70 | 98.30 | 1.13 10 | 0.28 | 17,842 | 232 | 1.30 | 98.70 | 1.43 8 | 0.29 | 9,556 | 59 | 0.62 | 99.38 | 1.59 4 | 0.29 | 20,212 | 135 | 0.67 | 99.33 | 2.00 | | | | | | 5 | 0.66 | 23,680 | 336 | 1.42 | 98.58 | 1.42 7 | 0.96 | 30,200 | 475 | 1.57 | 98.43 | 1.74 4 | 1.25 | 37,587 | 496 | 1.32 | 98.68 | 2.81 ------------+----------+----------+---------+----------+--------+----------- The following table shows the bacterial efficiencies with turbid, muddy, and thick waters, with substantially equal quantities of sulphate of alumina: -------------------------------+------------------------------------- Grains of Sulphate of Alumina.|Corresponding Bacterial Efficiencies. ----------+----------+---------+-----------+----------+-------------- Turbid. | Muddy. | Thick. | Turbid. | Muddy. | Thick. ----------+----------+---------+-----------+----------+-------------- WARREN FILTER. 0.42 | 0.36 | | 93.00 | 95.27 | 0.84 | 0.85 | | 98.36 | 97.46 | 1.11 | 1.13 | | 98.78 | 98.60 | 1.58 | 1.73 | 1.74 | 98.63 | 99.20 | 98.55 | 2.38 | 2.64 | | 99.43 | 99.70 | 4.30 | 8.16 | | 97.89 | 96.70