Thus far our various methods of artificial lighting have been very simple. At first men burned the pitch from the pine, and it produced a flame; then they burned olive oil through a wick, and it gave forth a flame. The tallow in the candle was burned through a wick, and it made a light; the whale oil in the lamp was burned by means of a wick, and a light was the result. In the same way refined petroleum, which we call kerosene, was burned by means of a wick, and that gave a strong light. These methods of lighting were all very similar. We come now to a real invention. What would a boy of the year 1800, could he return to the earth, say to see you strike a match, turn a stopcock, and light the gas as you do to-day? He has never seen a match. He is just as ignorant of a stopcock, and surely it would be difficult for him to understand the burning of the gas. Many things would need to be explained to this boy of a hundred years ago. He must be told all about the production of illuminating gas, the storing of that gas under pressure, the transportation of it to the place where the light is wanted, and the proper apparatus for turning it on, setting it on fire, and regulating its pressure so as to produce a steady, uniform light. Before the year 1700 Dr. John Clayton, an Englishman, prepared gas from bituminous coal, collected it, and burned it for the amusement of his friends. An English bishop in 1767 showed how gas could be produced from coal and how it might be conveyed in tubes. These were the first two steps toward our present almost universal illumination by gas: making gas and conveying it in tubes. The real inventor of practical gas-lighting was William Murdoch, of Cornwall, England, who sometime before the year 1800 carried pipes through his house and office, and lighted the various rooms with gas which he had made from coal. Indeed, Murdoch did more than this: he lighted with his new gas a small steam carriage in which he rode to and from his mines. In 1802 he first publicly exhibited this gas-lighting in Ayrshire, Scotland, and showed two immense flames from coal gas. Nor did he stop here, for in 1805 he succeeded in lighting some cotton mills by the same method. In our country various experiments were made, but without any practical result until 1821, when illuminating gas was successfully manufactured and used in Baltimore. In 1827 the New York Gaslight Company introduced this new method into many houses and sold the gas to the people for lighting purposes.