64 On the Safe-lamp, and the Ventilation of Mines. 



The Safe-lamp. 



An inspection of fig. 1. will explain the structure of the safe- 

 lamp proposed by me. A is a cylindrical glass envelope, or one 

 of horn secured from accidental external injury hv being sur- 

 rounded with wires; a is the flexible hose which feeds the lamp, 

 by air contiguous to the floor of the mine. I have already con- 

 tended for the priority of suggesting the structure of a safety- 

 lamp founded on the specific levity of the fire-damp, and a 

 comparison of dates will confirm to me the a\vard. /; is a hol- 

 low metallic ball attached to the chimney. This spherical bulb 

 will be kept constantly supplied with carbonic acid gas and 

 azote, the products of combustion; and tlierelbre should a dis- 

 lodgement of fire-damp from the floor of the mine take place, 

 and the included flame expand upwards, it would never come in 

 contact with the external atmosphere above, for it would cease 

 to be flame so soon as it encountered the mephitic airs and 

 aqueous vapour included in the ball of the chiuiucv. As for ex- 

 plosion, this would be prevented by the heated rarefied medium 

 within the cylinder of the lamp. Experiment taught me also 

 (and I was led to it, by considering that a fowling-piece not cor- 

 rectly and evenly bored would inevitably burst) that explosive 

 mixtures of gases would not pass through a spiral tube; and such 

 a metallic canal, I also proposed for a chimney. 



The Choke-damp. 



For the removal of the carbonic acid gas I suggested the pro- 

 priety of sinking a well in the lowest part of the pavement of the 

 mine, as its recipient, and inclined grooves or gutters termina- 

 ting here, to conduct the gas to this reservoir, from all parts of the 

 field of coal. As carbonic acid gas may be pumped out like li- 

 quid matter, the appendage of an air-pump to the steam-engine, 

 with a hose connecting the pump-tree with the cavity in ques- 

 tion, would as effectually remove it as if it were so much water; 

 this I have made repeatedly the subject of experiment: — or, in 

 lieu of this, a cistern partly filled with lime-water in the well 

 in question would, by being agitated at intervals (by vertical 

 machinery like that of a common barrel churn), be made to con- 

 dense and absorb an estensive volume of the gas, and the chalk 

 so formed would be precipitated. A fresh portion of quicklime 

 being thrown into the cistern and agitated therein, would yield 

 lime-water, and be made to absorb a further volume, and so on. 



The Fire-damp. 



An examination of fig. 2. will convey an idea of the proposed 



apparatus. 



