DISCOVERT Or COAL GAS.] 



UNDULATORY FORCES. LIGHT. 



115 



Greeks were really acquainted with a mode of generating 

 gas, and that the chief priests took advantage of such 

 knowledge in exciting the veneration of the people. The 

 altar in the temple of JEgina is described by Dr. Dodwell 

 as having a round hole, thirteen inches in diameter, cut 

 out of the top of it. This hole communicates with 

 another which passes down through the solid stone to 

 the depth of several feet, and there it opens into a 

 cavity which is supposed to have contained fire that was 

 always burning. He says that nothing more was neces- 

 sary than to pour oil into the upper opening ; and as it 

 trickled down, it would be converted into gas, which 

 would burst forth as flame, and appear to have a miracu- 

 lous origin. But however possible, or even probable, 

 the truth of this supposition may appear to be, it is 

 certain that nothing practical was undertaken in Europe 

 until the beginning of the 17th century, when Van 

 Helmont, the physician and alchymist of Vilvorden, was 

 led, in the course of his investigations, to expose a 

 quantity of animal and vegetable matter to the action of 

 heat in a closed vessel. By these means he obtained a 

 "vapour," or "spirit," that burnt with a bright flame; 

 but he little imagined that this gaz fuliginotum, as he 

 termed the vapour, would one day become an agent of 

 general illumination. Nor even at a much later period 

 namely, in the year 1726 when Dr. Hales informed the 

 chemists of his time, that by distilling a few grains of 

 Newcastle coal, he had obtained an equal number of 

 uchcs of inflammable air, could it be supposed 

 that a similar experiment, on a very gigantic scale, would 

 be daily performed in every city in Europe, and that 

 - of cubic feet of that subtle, inflammable material 

 would be made to traverse, unseen, along the highways 

 of the land, and be the means of lighting them up into 

 I an almost perpetual day. 



Again, we may take up the history of our subject 

 from another important discovery. Some time before 

 the death of the Honourable Robert Boyle (1601), a 

 letter was written to him by the Rev. Dr. Clayton, on 

 the subject of distilling pit-coaL That letter was pub- 

 lished many years afterwards in 1739 in the Trans- 

 actions of the Royal Society ; and the author states, that 

 from an examination of some inflammable vapours which 

 were given off from a ditch near Wigan in Lancashire 

 vapours which had been collected and examined by 

 Thomas Shirley in 1<>.">9 he was led to conclude that 

 they came from the coal of the neighbourhood, which 

 was acted on by terrestrial heat. Accordingly, he ob- 

 tained a portion of the coal, and distilled it in a retort 

 over an open fire. By this means he obtained a ' ' phlegm, " 

 which flint passed over ; then a " black ore ;" and lastly 

 "spirit," which he could nowise condense, for it 

 forced the luting of hit apparatus, and broke his glasses. 

 This "spirit" wa* coal gas; and on discovering its in- 

 flammable nature, he was in the habit of collecting it in 

 bladders and oiled silk bags, and thus preserving it for 

 the amusement of his friends. 



At yet, however, ho had not learnt to burn it from a 

 metallic jet, for he was accustomed to prick a hole in the 

 bag, and then to set tire to the gas as it issued forth. 

 For a period of more than fifty years these interesting 

 facts were allowed to slumber, and no one entertained 

 the idea of applying them to any useful purpose. At 

 length, in the year 1792, just one hundred years after 

 Boyle's death, an ingenious engineer and miner nf 

 Cornwall, whose name was Murdoch, conceived the 

 notion that gas might be conveyed through pipes to a 

 distance, and be thus employed as an illuminating agent. 

 Acting upon this idea, it was not long before he had the 

 satisfaction of seeing his house and offices at Redruth 

 li'.'Mod up with Dr. Clayton's "subtle spirit." He also 

 collected the gas in bladders, and used it as a means of 

 lighting himself along the road between the mines and 

 his own house ; for which piece of ingenuity he acquired 

 the rfjiuUtion of a wizard. Soon after this, Mr. Mur- 

 doch was employed in the establishment of the celebrated 

 ten, Messrs. Bolton and Watt. There he erected 

 apparatus for the manufacture of gas ; and at the peace 

 of Amiens, in 1802, he lighted up their factory for the 



first time with this agent. About a year afterwards, 

 gas was generally employed in all the workshops of the 

 factory; and in 1804 he set up a similar apparatus iii 

 several of the large cotton-mills of Lancashire one of 

 the earliest of which was the establishment of Messrs. 

 Phillips and Lee at Manchester. 



Ten years after this in 1813 the manufacture of gas 

 had extended to London, and in that year Westminster- 

 bridge was lighted with it. Mr. Clegg gives an account 

 of the horrors of the lamplighters when they first beheld 

 the burning gas, and how he was obliged to light the 

 lamps himself for some time, on account of the fears of 

 the people. Even such men as Sir Humphry Davy and 

 Sir Joseph Banks were unable, for many years after 

 this, to overcome the prejudices which existed in their 

 minds concerning it; and they thought the scheme a 

 wild and dangerous one. The public, however, soon 

 became reconciled to it ; and in 1814 the oil-lamps were 

 removed from the streets of St. Margaret, Westminster, 

 and gas-lights were put into their places. This was the 

 first parish that entered into a contract to have the 

 streets lighted with gas. 



In the same year the allied sovereigns came to this 

 country ; and as they were to be feted and feasted in no 

 ordinary manner, a great opportunity occurred for the 

 use of gas, where no other means of illumination could 

 be employed. On the ornamental water of St. James's 

 Park a magnificent pagoda was erected ; it was furnished 

 with thousands of jets of gas ; and in an instant, as if by 

 magic, they all burst forth into flame, and gave the 

 building the aspect of a brilliant fountain of fire. At 

 one of the City feasts, the Guildhall was lighted up in a 

 similar manner ; and we are told by one of the journals 

 of the time, that the light was "clear as summer's noon, 

 but soft and undazzling as moonlight, forming a magni- 

 ficent combination worthy the inauguration of the pre- 

 siding citizen of the great city." Up to that time the 

 gas was marvellously impure, ami its fu-tid odour proved 

 au insurmountable barrier to its use in private houses, 

 tually the attention of chemists began to be direct. .1 

 to this point ; and as the processes of manufacture and 

 purification were perfected, the use of gas became more 

 il ; so that in 1822 there were four great companies 

 iliol in I/ondon, having forty-seven gasometers, 

 supplied by 1,315 retorts, which generated upwards of 

 397,000,000 cubic feet of gas annually, supplying about 

 61,000 private lamps, and 7,2li ]>uilie ones. In fiv<3 

 yean this quantity had nearly doubled itself ; and in ten 

 yean more it was doubled again; so that in the year 

 1837 it had acquired so much importance as to become 

 a subject for parliamentary investigation. In that y< ar 

 a paper was laid before a committee of the House of 

 Commons, by Mr. Hedley ; from which we gather, that 

 for lighting London and its suburbs, a capital of 

 2,800,000 was employed. This yielded a revenue of 

 450,000, and furnished an annual supply of 1,400,000,000 

 cubic feet of gas. Twelve years after this, wo are told 

 by Mr. Croll, in his evidence before the committee of the 

 House of Commons on the Great Central Bill, that the 

 consumption of gas in the metropolis, during the year 

 1849, was more than double that of the preceding esti- 

 mate ; for it amounted to 3,200,000,000 cubic feet aim 

 ally, of which the City alone consumed 500,000,000. 

 This was distributed to 2,678 public lights, and to a 

 multitude of private consumers. The area of the metro- 

 polis is about sixty-six square miles, and that of the City, 

 one mile. In the former space there are, according to 

 Mr. Barlow, ibout 2,400 miles of main-pipes, which run 

 along 1,600 miles of streets ; and in the latter there are 

 about 110 miles of main-pipes, which light up 75 miles 

 of streets. The surveyor to the Corporation states, in 

 one of his reports, that the length of the public way in 

 the City is only 51 miles, and that the lamps average 54 

 to each linear mile, or 1 in every 33 yards. But perhaps 

 the best estimate of the enormous extent to which tliis 

 branch of industry is carried on, may be formed from 

 a statement made by Dr. Hoffman, on the authority of 

 Mr. Lowe, who is one of the oldest gas engineers of the 

 present time. He says, that about 6,000,000 too* of 



