in Edinburgh) on the 23d March 1825. 87 



escaping during the precise interval when it has not been m 

 use in any other part of the house, for it is well known, and 

 will be proved in the subsequent part of this paper, that the 

 lights which are burning will indicate to the family that the 

 cms is discharging itself in some part of the house, and will, 

 Therefore, induce them either to apply for help to the Gas 

 Company, or to send a servant without a light to discover 

 the place of discharge, shut the cock, and ventilate the apart- 

 ment. If the escape happens during the day, when no lights 

 are burning in the house to give these indications, then there 

 is no danger whatever of an explosion, as there is no occasion 

 to carry a light about to discover the place of escape, or for any 

 other purposes. 



Having thus pointed out the nature of the danger which 

 may be apprehended from excessive and palpable negligence 

 on the part of the engineer and the consumer, we shall pro- 

 ceed to give an account of the explosion which took place in 

 the house of Colin Mackenzie, Esq. on the 23d March 1825. 

 In the area, and immediately under the stair leading to the 

 front door of Mr Mackenzie's house, there was a small out- 

 house B, Plate I. Fig. 1., about six feet high, and four feet 

 square, which was completely covered in, partly by the steps of 

 the stone stair above, and partly by a stone covering at the 

 back. It was plastered on the top inside, and had no outlet 

 whatever except a very small door D, with two small slits in 

 it, which opened into the area. The place was very close 

 and completely unventilated. It was used for cleaning shoes 

 and knives, and in it was placed the meter G, through which 

 the supply of gas for the whole house passed. A gas light b, 

 was most unfortunately fixed in this very small out-house, 

 and supplied by a quarter inch branch pipe, which termi- 

 nated in a bent brass tube, called a knee, the aperture of 

 which was three-eights of an inch in diameter. Into this knee 

 was inserted a jet burner, which is put into the brass knee like 

 the stopper into a wine decanter, and can be removed like it 

 at pleasure, being neither screwed nor soldered. 



On Saturday, the 1 9th of March, the inspector examined 

 the meter and the gas-fittings in the shoe-house, and through 

 the house. He ascertained that they were perfectly tight and 



