1888.] 071 Safety Lamps in Collieries. 209 



by a thick glass cylinder to increase the emission of light, and now 

 with a bonnet or shield to protect it from currents of air. The 

 " Mueseler," or Belgian type, is a " Clanny " with a central metallic 

 cone acting as a funnel to increase the draught, and therefore the 

 light. The " Marsaut," or the French type, is a bonneted or pro- 

 tected " Clanny," with two and three gauzes added to increase the 

 security. The number of lamps is legion. A new intake here, a 

 fresh egress there, a new direction to the currents of air feeding the 

 flame, a change in the form or character of the wick, a lock, a 

 different form of pricker, a shut-off or extinguisher (automatic or 

 manual), is quite sufficient to justify a new patent and a new name. 

 The Eoyal Commission experimented upon 250 different kinds of 

 lamps. 



Since the commencement of the year a new Act has come into 

 force rendering it unlawful to use the plain " Davy," " Stephenson," 

 or " Clanny " lamp in mines where safety lamps are necessary. 

 They must be shielded, and great numbers are being converted into 

 bonneted " Marsauts " and " Mueselers." They are also being con- 

 structed to burn the best vegetable oil (rape or colza), to which one- 

 third mineral oil is added, as recommended by the Eoyal Commission, 

 to enhance the light-giving power of the lamp. These converted 

 lamps have baffled all attempts to explode them in currents of 

 explosive gases of very high velocity, and under the most rigid tests. 



There are several objections to these oil lamps. They go out, or 

 are put out when danger exists ; they render that most important 

 and essential duty, examination of the roof, difficult and insufficient. 

 If they become extinguished by accident or design, much time is 

 necessarily wasted in getting them relighted, an operation that must 

 be done at or near the shaft, perhaps two miles away from the work- 

 ing face, and which therefore reduces the output of coal and the 

 earnings of the collier. The light they give, even at the best, is 

 very small — about one-third to half of a candle. 



There are several dangers present. The Eoyal Commission 

 said : — " The source of light within the lamp should be unable under 

 any circumstance, at all likely to occur in working coal to cause the 

 ignition of an inflammable mixture of fire-damp and air, even when 

 this is passing at a high velocity." But glasses break by water, 

 heat, falling coal, and accident. Joints get loose and bad even when 

 protected by asbestos washers. 



They prove a constant temptation to the thoughtless and callous 

 to get a light. The perfect light does not exist at present, but while 

 these mechanical lamps are very excellent in their way, electricity 

 seems likely to step in and supply their deficiencies and fill a 

 decided want. An electric lamp can be made to give any desired 

 amount of light, but anything between half a candle and a candle 

 seems easily attainable, and such a light can be maintained steady 

 and bright in explosive gases and in strong currents of air. They 

 are simple in construction, easy of inspection ; they are not likely 



