448 Mr. W. Galloway on Safety -Lamps. [June 18, 



into a horizontal borehole which had struck a blower, and the firedamp 

 was conducted in tubes to a collecting vessel at a short distance. I soon 

 found that this firedamp was very impure, as a mixture of one part of it 

 with thirteen parts of air was not explosive ; however, I made a number 

 of experiments in the mine with both sets of apparatus (figs. 1 & 2, 

 Plate VI.), but did not succeed in passing the flame, except perhaps in one 

 doubtful instance with the larger apparatus, when the gas issuing from 

 the Bunsen burner was not set on fire. 



The next experiments with firedamp were made in the C Pit, Hebburn 

 Colliery, near Newcastle-on-Tyne. The gas, which issued from a bore- 

 hole similar to that in the Barleith Pit, was collected in the same way, 

 and conveyed in the collecting vessel to a convenient place near the 

 stables, where naked lights could be used. The experiments with both 

 sets of apparatus were quite successful, the quantity of gunpowder, 

 required being, in each case, the same as when coal-gas was used. The 

 Davy lamp employed in the experiments with the larger apparatus 

 belonged to the colliery, and was in constant use below ground. At the 

 fifth trial (when I had ascertained the quantity of gunpowder required) 

 the flame passed through the wire gauze, set fire to the paper tied over 

 the end k, and passing backwards down the tube /, kindled the gas 

 issuing from the Bunsen burner. My brother, Mr. E/. L. Galloway, who 

 was the resident viewer of the colliery at that time, was observing the 

 lamp through the window h when the shot by which the flame was 

 passed was fired. The flame of the wick, which was of ordinary dimen- 

 sions before it was surrounded by the explosive mixture, had sent up a 

 long smoky point to near the t^p of the gauze, which showed that the 

 explosive mixture was composed of about 1 part of firedamp to 12 or 13 

 parts of air. The lamp was carefully examined after the trial, and was 

 found to be in good order. 



The Directors of the Company to whom the colliery belongs were un- 

 willing to allow any further experiments to be made in the mine, so that 

 this series had to be abandoned before any more results had been obtained. 



Following are the analyses of the firedamp used in the foregoing 

 experiments. The sample of gas from the Barleith blower was collected 

 by myself at the time the experiments were being made, and analyzed by 

 Dr. T. E. Thorpe, of Glasgow; that from the Hebburn blower was 

 collected by my brother several weeks before the experiments, and was 

 analyzed by Dr. "Wright, of St. Mary's Hospital, London. 



Barleith. Hebburn. 



Light carburetted hydrogen 75-86 



Carbonic acid 1-31 



Olefiant gas 



Carbonic oxide 



Oxygen 



Nitrogen.... 22-83 



100-00 100-00 



