In spite of all the flatteries and attentions which were showered upon him, Davy stuck manfully to his profession; and if his reputation was somewhat artificial and exaggerated at the commencement, he amply earned and consolidated it by his valuable contributions to science during the rest of his career. The name of Humphrey Davy will always be best known from its association with the ingenious safety lamp which he invented, and which well entitles him to rank as one of the benefactors of mankind. It was in the year 1815 that Davy first turned his attention to this subject. Of frequent occurrence from the very first commencement of coal-mining, the number of accidents from fire-damp had been sadly multiplied by the increase of mining operations consequent on the introduction of the steam engine. The dreadful character of some of the explosions which occurred about this time, the appalling number of lives lost, and the wide-spread desolation in some of the colliery districts which they had occasioned, weighed heavily on the minds of all connected with such matters. Not merely were the feelings of humanity wounded by the terrible and constant danger to which the intrepid miners were exposed, but it began to be gravely questioned whether the high rate of wage which the collier required to pay him not only for his labour, but for the risk he ran, would admit of the mines being profitably worked. It was felt that some strenuous effort must be made to preserve the miners from their awful foe. Davy was then in the plenitude of his reputation, and a committee of coal-owners besought him to investigate the subject, and if possible provide some preventative against explosions. Davy at once went to the north of England, visited a number of the principal pits, obtained specimens of fire-damp, analyzed them carefully, and having discovered the peculiarities of this element of destruction, after numerous experiments devised the safety-lamp as its antagonist. The principles upon which this contrivance rests, are the modification of the explosive tendencies of fire-damp (the inflammable gas in mines) when mixed with carbonic acid and nitrogen; and the obstacle presented to the passage of an explosion, if it should occur, through a hole less than the seventh of an inch in diameter; and accordingly, while the small oil lamp in burning itself mixes the surrounding gas with carbonic acid and nitrogen, the cylinder of wire-gauze which surrounds it prevents the escape of any explosion. It is curious that George Stephenson, the celebrated engineer, about the same time, hit on much the same expedient.