Mr Bald 07i the spontaneous emissions of Gas. 73 



the purpose of lighting their candles, it had the effect of gra- 

 dually perforating the solid coal, and forming a recess like a 

 bason, but the coal never appeared to be ignited ; on the other 

 hand, when blowers have ignited, their strength and force of 

 flame are such, that they have acted like an immense blow- 

 pipe, and set on fire the coal at the distance of twelve feet 

 from the spot where the gas issued. 



When the engine-pit at Preston Island was putting down, 

 which is situated upon the estate of Sir Robert Preston, Bart, 

 near the town of Culross, and about three-fourths of a mile 

 within the high water mark of the river Forth, I went several 

 times down this pit to see theissuingof the inflammable gas. We 

 knew that the strata had not been opened up before ; but there 

 were many cutters, fissures and beds in the rock, and long before 

 the miners reached the coal, the inflammable gas issued through 

 the fissures and beds of the sandstone rock, and made the water 

 in the pit boil like a pot, or not unlike liquor in a violent state 

 of fermentation. During the process of sinking, the workmen 

 observed air bubbling up in many places through the sludge 

 or sleech which composed the surface which was laid dry at 

 every ebb tide, and at a considerable distance from the pit ; 

 and it was a common amusement of the workmen to make 

 cones of clay, each perforated with a small hole, and put them 

 over the places where the gas issued. These they ignited, and 

 they flamed like large coal-gas burners. 



Upon the miners reaching the coal it proved to be very full 

 of inflammable air, and several severe and fatal accidents were 

 the consequence ; one blast was so remarkably strong as to 

 kill a workman who was standing at the surface by the side of 

 the pit. 



I have also to remark, that it is a common occurrence where 

 bores are put down to coals which are full of inflammable gas, 

 and intersected with fissures, to find a strong issue of gas at the 

 surface, and this will continue to be emitted for years. A re- 

 markable instance of this happened in putting down a bore in 

 the trough of the Glasgow coal-field some miles east of the city. 

 When the gas was ignited, the discharge was such as to pro- 

 duce a flame of from eight to ten feet in height. From this 

 we infer that a large cavity is not necessary for producing the 



