C—2.

Table showing an Analysis of the Ventilation in the Principal Collieries of the Dominion made by the Chief Inspector during the early part of 1920.

50

Narae of Colliery. Place of Observation. Date. Quantity of Air passing per Minute. " as ti £5? yc, Analysi Air Quantity of Air I per Person per Minute.* is of such Return by Dominion Analyst. Remarks. CO 2 . Oxygen, i CH4. North Island. Taupiri Extended . . Cub. ft, 15,765 10.881 3,710 13,211 10.368 8,028 87,000 39 14 13 43 29 20 Cub. ft, 404 777 284 307 354 401 Per j Per Cent, j Cent. C 0 15 | 20-36 ( 0-03 20-88 007 20-70 i t 008 20-66 010 20-70 010 21-51 Per Cent. 006 Per 006 0-14 009 .. ; No. 4 level, west side, return No. 5 dip, west side, return No. 5, new dip, and No. 6, west side, return No. 2 district, north side, return No. 1, tail-rope district, north side, return No. 7 district, north side, return Main return at fan 9/4/20 9/4/20 9/4/20 10/4/20 10/4/20 10/4/20 8/4/20 0-14 Atmospheric purity. 009 Effective ventilation, 71-2 per cent. ; water-gauge at fan, 2-5 in. Atmospheric purity. Pukemiro North district return Straight heading, left return Straight heading, right return Main return at fan 12/4/20 12/4/20 12/4/20 12/4/20 12,274 13,740 1 1,736 40.837 40 22 20 307 624 587 003 1 20-70 016 j 20-69 t 0-10 j 20-69 Effective ventilation, 92-2 per cent.; water-gauge at fan, 1 in. Rotowaro No. 3 south return No. 4 south return Main jig return Main return at fan No. 4 section (Siberia) return Pillars section return Main return at fan 13/4/20 13/4/20 13/4/20 13/4/20 14/4/20 14/4/20 14/4/20 9.984 4,257 4,150 26,845 16,200 3,672 23,324 40 12 32 43 8 9 1 249 355 130 348 384 007 | 20-78 t 0-15 I 20-88 t 0-07 I 20-72 Due to leakage and fan running at reduced speed. Effective ventilation, 68-5 per cent. Waipa 1 " . Effective ventilation, 85-1 per cent. South Island. Liverpool No. 1 Upper seam, No. 3 bank return Upper seam, crosscut return Morgan seam, east return Morgan seam, west return Main return at fan No. 1 district return No. 2 district return No. 3 district return Main return at fan Main return at fan 20/5/20 20/5/20 20/5/20 20/5/20 20/5/20 20/5/20 20/5/20 20/5/20 20/5/20 5/2/20 10,722 6,312 15,631 9,712 64,128 8 540 10,260 5,675 31,266 3,782 29 23 23 27 34 13 12 3 1 Effective ventilation, 66 per cent. • • : H» Liverpool No. 3 ... j 369 274 680 360 334 249 436 400 0-10 20-38 0-05 20-83 012 20-72 •" I Effective ventilation, 78 per cent. s» • • Brunner . . * The quantity of air per person is obtained by dividing the total quantity circulating, after an allowance of 600 ft. per horse has been deducted. t No sample taken; the mine-air was obviously wbolesome.