JANUARY. Illuminating Power in Amount of Impurity. Standard Sperm Candles. Sulphuretted Ammonia per 100 Sulphur per Hydrogen. feet, grains. 100 feet, grains. 1 20.7 None 7.4 23 0 2 21.1 „ 5.0 23.3 3 20.3 „ 4.6 ... 5 20.2 „ 7.5 23.7 6 22.2 „ 6.4 23.1 7 22.4 „ 4.6 22.1 8 22.4 „ 4.2 22.5 9 22.7 „ 3.8 21.4 10 21.9 „ 3.2 21.8 12 22.7 „ ... 22.3 13 22.2 „ 4.6 22.6 14 22.2 „ 5.0 18.4 15 22 3 „ 5.2 15.1 16 22.1 „ 5.2 20.3 17 20.2 „ 3.2 19.7 19 20.7 „ 2.0 21.0 20 21.0 „ 4.0 22.4 21 Not received. 22 19.7 „ 4.6 22.8 23 20 8 „ 2.4 23.3 24 19.6 „ 2.2 24.2 26 22 2 „ 2.4 24.0 27 Not received. 28 20.2 „ 4.0 23.6 29 20.9 „ 3.0 17.3 30 21.0 „ 2.6 24.3 31 20.5 „ 1.7 24.0