Mr. Murdock is, however, better known to the public by his application of the light of coal gas to general purposes. Although this gas had been well known, and obtained both naturally and artificially more than half a century before his time, no attempt had as yet been made to turn the discovery to any useful account. In the year 1792 Murdock first employed coal gas for the purpose of lighting his house and offices at Redruth; he made it serve also as a lantern, by attaching a bladder with a tube mouthpiece under the bottom of a glass shade, which contrivance used to light him across the moors when returning home at night from the mining engines he was erecting in different parts of the district. After various experiments which proved the economy and convenience of light so obtained, he perfected his apparatus and made a public exhibition of it by lighting up the front of Boulton and Watt's manufactory at Soho, on the occasion of the general illumination for the peace of Amiens, in 1802. He subsequently lighted up some cotton mills at Manchester, beginning with Messrs. Phillips and Lee's, and published a paper on the subject in the 'Philosophical Transactions' of 1808, for which the Royal Society presented him with the Rumford gold medal. In 1798 Murdock returned to take up his permanent residence at Soho, superintending the machinery there, and occasionally the erection of engines at a distance, among which may be mentioned those of the New River Head, Lambeth, Chelsea, Southwark, East London, West Middlesex, and other waterworks. In the following year he took out a patent for improvements in boring cylinders and in the manufacture of steam casings; this patent also included the double =D= slide valve and a rotary engine. Amongst other inventions and discoveries of Murdock's are: a plan for boring stone pipes for water, and cutting columns out of solid blocks of stone (for which he took a patent in 1810); a pneumatic lift working by compressed air; and a cast iron cement, which he was led to discover by the accidental observance of some iron borings and sal-ammoniac, which had got mixed in his tool-chest and rusted a sword blade nearly through. He also made use of compressed air to ring the bells in his house; a plan which so pleased Sir Walter Scott, to whom it had been described, that he had his house at Abbotsford fitted up in a similar manner. Murdock likewise discovered a substitute for isinglass, and when in London for the purpose of explaining to the brewers the nature of his discovery, occupied very handsome apartments. Being, however, at all times absorbed in whatever subject he had in hand, he little respected the splendour of his drawing-room, but proceeded with his experiments as if in the laboratory at Soho, quite unconscious of the mischief he was doing. This resulted in his abrupt dismissal from the apartments by the enraged landlady, who one morning, on calling in to receive orders, was