24 Scientific Societies. 



fire-damp in mines, the great philosopher had no accident to help 

 him, Davy, then on a shooting tour in Scotland, at once took the 

 matter up. He visited mines and coal-pits on his southward 

 journey, studied the nature of the accidents, and took away with 

 him specimens of the inflammable air. He then, both by induc- 

 tion and deduction, resolutely attacked the problem before him on 

 all sides, exhausting all its conditions. There were two conceiv- 

 able courses, the one to get rid of the fire-damp, the other to 

 render it innocuous. The first plan was impossible, since a single 

 blow of the pickaxe might at any time open a vent which should 

 fill a whole mine with the explosive material ; the only other 

 plan then was to prevent the explosion when the fire-damp was 

 present. To find out how this should be done, Davy analysed 

 the fire-damp, and among a multitude of other discoveries respect- 

 ing it found, first, that it required a very considerable degree of 

 heat for its ignition, and then that it would not explode in a narrow 

 tube, because the metallic sides of the tube cooled the combustible 

 gases of which the fire damp is composed. Pursuing this indi- 

 cation step by step, he found that wire gauze was equally effectual 

 in reducing the temperature of flame below the point of ignition. 

 Here then was the idea of the safety lamp, and a day or two after 

 it was & fait accompli. By this simple invention it is probable 

 that thousands of lives have been saved, and instead of working as 

 before in deep discomfort by the dim uncertain scintillations of the 

 steel mill, in which "an intermittent light was produced by the 

 rotation of a steel wheel against a flint," the miner now works in 

 perfect safety by a steady glow, when he is perhaps in the midst of 

 explosive gases, and a mile below the light of day in the bowels 

 of the earth, protected by so delicate a medium, and so invisible 

 an influence, from a power as terrific as the earthquake and the 

 lightning flash. 



Once more. When the little idle boy, James Watt, was once 

 trifling with his spoon, and watching how the steam from a kettle 

 was condensed in drops upon its silver bowl ; his aunt very 

 naturally scolded him as a little dreamy trifler. Yet although for 

 that little dreamy trifler it was a moment of dawning inspiration, 

 how long, how elaborate, how self-denying, how intense was that 

 series of labours which converted a chance observation into " the 

 masterpiece of human skill," and by presenting man with the 

 steam engine, altered the conditions of life, and perhaps the very 

 destinies of nations throughout the globe. 



What do we see in all these true tales ? We see, among other 

 things, how many ages, He — who creates in a thousand realms, on 

 Alpine crests, and in desert solitudes, millions of glories which 

 gladden no human heart — how long that Almighty Father is con- 



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