1874.] 



Mr. W. Galloway on Safety -Lamps. 



441 



XIX. "Experiments with Safety-Lamps/' By WILLIAM GALLOWAY, 

 Inspector of Mines. Communicated by R. H. SCOTT, F.E/.S. 

 Received May 4, 1874. 



After the occurrence of a great colliery-explosion it is usually very 

 difficult, and sometimes impossible, to arrive at a satisfactory conclusion 

 as to what were the causes which probably led to the catastrophe, and 

 when safety-lamps have been exclusively used by the workmen its origin 

 seems to be shrouded in mystery. The explosions which happened at 

 Eisca, Morfa, Cethin, High Brooks, and Pelton Collieries between the 

 1st of March, 1860, and the 21st of October, 1866, appeared to be alto- 

 gether inexplicable ; and, in the last two cases, when all the safety-lamps 

 were found locked after the accident, no attempts were made to explain 

 the phenomena. 



On the 12th of December, 1866, however, the great explosion took 

 place at the Oaks Colliery, and fortunately several of the men who 

 survived could give an account of some of the circumstances wiiich 

 immediately preceded it. A stone drift had been cut from near the 

 bottom of the downcast-shafts to within a few feet of one of the intake- 

 airways, and shortly before the accident a shot-hole was drilled at its 

 inner end, and charged with a considerable quantity* of gunpowder; the 

 men whp were about the pit-bottom were warned into a sheltered place ; 

 the shot was fired, and in a few seconds afterwards the shock of the 

 explosion was felt. It was ascertained subsequently that a part of the 

 rock at the bottom of the shot-hole had been blown into the intake-airway, 

 leaving the tamping intact, so that the concussion of the air would be 

 almost as great as if the tamping alone had been blown out. 



A coincidence so remarkable as this attracted considerable attention, 

 and after every great explosion which has happened since the Oaks' a 

 search has evidently been made for some evidence of recent shot-firing. 

 The following Table will give an idea of the magnitude of the important 

 explosions which have happened within recent years, and of some of the 

 circumstances under which they occurred. 



Synopsis of great explosions since 1860. 



to 6 Ibs. 



Eeports of the Inspectors of Mines for the year 1866, p. 43. 



2L2 



