On January 11th, 1816, he read a second paper to the Royal Society, entitled, “An account of an invention for giving light in explosive mixtures of fire-damp in coal mines by consuming the fire-damp,” in which he shows that the tubes or canals as well as the sides of the lanterns may be replaced by cages or cylinders of wire gauze. The inflammable mixture will readily pass through the meshes of the gauze and will burn within it, filling the cylinder with a bright flame, but no explosion will pass outwards, even although the wire becomes heated to redness. A fortnight later he read a third paper to the Society, “On the Combustion of Explosive Mixtures confined by Wire Gauze, with some Observations on Flame,” in which he gives the results of further inquiries respecting the limits of the size of the apertures, and of the wire in the metallic gauze required to shield the flame of an oil-lamp, and describes a number of illustrations of the action of the gauze in lowering the temperature of the explosive mixture below the point of ignition. Some of these illustrations are now among the stock experiments of the lecture theatre. He offers some observations concerning the essential nature of flame, and concludes by informing the Society that his “cylinder lamps [_i.e._ lamps of which the flames are enclosed within a cylinder of gauze: see Fig. 11, p. 199] have been tried in two of the most dangerous mines near Newcastle with perfect success.” The form which the lamp finally took in the hands of Mr. Newman, the instrument-maker, is seen on p. 200. The trials above referred to were first made by Mr. Matthias Dunn and the indefatigable Mr. Hodgson in the Hebburn Colliery, and shortly afterwards by Mr. John Buddle in the Wall’s End Colliery. Mr. Buddle has placed on record his impressions of his first experience. “I first tried it,” he says, “in an explosive mixture on the surface; and then took it into a mine; ... it is impossible for me to express my feelings at the time when I first suspended the lamp in the mine and saw it red hot.... I said to those around me ‘We have at last subdued this monster.’” Some months afterwards Davy accompanied Mr. Buddle into the pit and saw his lamp in actual use. “Sir Humphry was delighted,” says Mr. Buddle, “and I was overwhelmed with feelings of gratitude to that great genius which had produced it.” Further testimony of Mr. Buddle’s appreciation of this memorable invention may be seen from the following extract from a letter by him to Davy. It is not only interesting in view of Davy’s remark that “the evidence of the use of a practical discovery is of most value when furnished by practical men,” but also as showing the rapidity with which the discovery was taken advantage of:-- “Walls End Colliery, Newcastle, _June 1st, 1816_.