WHITE-DAMP IN COAL' MINES

Otago Daily Times, Issue 14000, 5 September 1907, Page 7

WHITE-DAMP IN COAL' MINES

INTERVIEW WITH AN EXPERT ! MINING ENGINEER.. '

(Psou Our Special Reporter.) '• '. ~. RIYERTON, September 4. ! . ,■>+. An interesting point cropped'up at tlia Nightcaps Royal Commipion inquiry yester-'. ; .y! :•$ day. Sir Lloyd, the mino manager, stated in his ovidenoo that whilst 1 per cent of • h monoxide was fatal to life a lamp would - : keep alight in it up to 12 per .cent. The - v perccntago waa ■ challenged by one oi two poisons, in the court, but Mr' Lloyd was'." ■>' found to bo correct. For the information • "■ of miners and others interested a Time3 V ; ' reporter interviewed an expert last iiight, . . ..Si and obtained from him a brief summary of -v - vTm all the standard authorities upon the subject. ' , .' V Si of .inorganic, chemistry and the gases : met'.;k: 'with in coal mines. It appears that candlea : i \' - and lamps will burn,in the noxious W'hite- .' . : damp, or carbon monoxide, in the air with- !■•' out being visibly atlceted at a time 'when ' ; thi mixturo is fatal to life. When carbon • ' dioxide, oi' black-Amp, is present also, as wis'tho case at Nightcaps in the recent V disaster, half of 1 .per cent, of carbon mon-v oxido is fatal to human beings. Without the. i: rOl j presonco of black-damp 1 per cent, of carbon. v ;:n ■monoxide' is 'immediately fatal to life,,. It . . cannot'bo dotected by tlio fluno of A lamf/ ' V until. thero is' ahout 12 per oott& ,'iritho!' atmasphoro. To become' explosive ■ this gaa i must he mixed with the air in the propor-" •. • tioA of ono volume.of carbon monoxido to 2J volumes of air. This gas. is colourlcw > v and tasteless, but possesses a''slight -smell.! vr/y.'v.ri. When present in largo quantities •it is ; in , '.' v-. : !..S itself combustible, burning with a beautiful blue flamo and forming carbon dioxide. It. is ' easily kindled.; The combustions of) ... a' •this'gas'm -ofton witnessed in a colco or - : r-f charcoal fire. The carbonio acid produced in the lower part of tho firo is converted-' '••• ■ -.v! into eiu-bonio oxide as it passes up from 1 . tho hot embers, and will afterwards burn .with a pale blud flame whero it. meets theair.. ,Tho French Fire-damp Commission' ••• gives.the -temperature of ignition of this gas:at 122deg Fahr. In mines whore tho . '.i.Mvwitilation is good and constantly mam-■ taincd'so this gas is not met-inCh.-'. Tlis'>^ s ' British Coal Commissioner? appointed ;'to-' inquiro into accidents in mines state in . : ; their rep'ort that when a coal seam; or tlio . - jjt gob; is on firo the gas is produced' in largo quantities, owinc; to the imporfect combus- v tion through' efforts made to exclude ;the - air from the-fire. Fortunatoly this-gas is very rarely found in mines except under tho above exceptional circumstances