This lantern was formed by filling a bladder with gas and fixing a jet to the mouthpiece at the bottom of a glass lantern, with the bladder hanging underneath.
Having satisfied himself as to the superior economy of coal gas, as compared with oils and tallow, for the purposes of artificial illumination, Murdock mentioned the subject to Mr.James Watt, jun., during a brief visit to Soho in 1794, and urged the propriety of taking out a patent.

Watt was, however, indifferent to taking out any further patents, being still engaged in contesting with the Cornish mine-owners his father's rights to the user of the condensing steam-engine.
Nothing definite was done at the time.

Murdock returned to Cornwall and continued his experiments.

At the end of the same year he exhibited to Mr.Phillips and others, at the Polgooth mine, his apparatus for extracting gases from coal and other substances, showed it in use, lit the gas which issued from the burner, and showed its "strong and beautiful light." He afterwards exhibited the same apparatus to Tregelles and others at the Neath Abbey Company's ironworks in Glamorganshire.
Murdock returned to Soho in 1798, to take up his permanent residence in the neighbourhood.

When the mine owners heard of his intention to leave Cornwall, they combined in offering him a handsome salary provided he would remain in the county; but his attachment to his friends at Soho would not allow him to comply with their request.