TRANSACTIONS OF SECTION G. 785 



Further details of the improved condition, for the purposes of navigation, are also 

 added in the paper. 



But another object of the paper is to endeavour to provide data for the recal- 

 culation of the data of the tidal rep-iiue, as amended by the above results, by what 

 is known as the method of ' harmonic analysis.' 



This method of ' harmonic analysis ' of the tides Avas first brought before the 

 British Association in 187:2 in a long report by Sir Williiim Thomson (now Lord 

 Kelvin), I'rofessor J.C. Adams, Professor Kankine, and others. A further report, 

 however, on the subject, and illustrative of the method, as used in the reduction 

 of the Indian tidal observations, was presented at the 1883 meetinff in Southport 

 by Professor (i. II. Darwin and Professor J. G. Adams. 



yince then, in 1885, I'rofessor G. H. Darwin has communicated to the Itoyal 

 Societj' the data, resulting from the harmonic analysis of the tides at Liverpool. 



It is urged, however — and apparently on frood authority — that the actual data 

 now afforded by the tidal regime of the Mersej', resulting from the changes 

 referred to at the commencement of the paper, are such as to render it advisable 

 to again submit the Mersey tides to a further examination by ' harmonic ana- 

 lysis.' 



The writer would suggest that a Committee might be formed, with the 

 object of obtaining the necessary Tidal data, and in a form suitable for Harmonic 

 Analysis thereof. 



9. History of the Discovery of Natural Gas in Sussex, Heathfield District, 



By Richard Pearson. 



The first find of gas which has come to my knowledge was made in 1836 at 

 Hawkhurst in West Sussex. 



Natural gas next appeared during the famous sub-Wealden boring of 1873-75, 

 at a place called Netherfield. The sub-Wealden was started to commemorate the 

 visit of the British Association to Brighton, 1872. Mr. Topley records at 603 feet 

 a bed 1 foot thick, very rich in petroleum. This was in the lummeridge clay, 

 390 feet from the surface. 



Willet records on this bore : ' Indications of petroleum became more distinct 

 at about 1 60 feet from top of the Kimmeridge clay ; all below that depth is 

 more or less impregnated with petroleum.' 



Natural gas was not used to any great extent in America before 1885. It was 

 about that date that Mr. Andrew Carnegie used natural gas in his steelworks. 



At Heathtield, some time ago, a firm of well-drillers were boring a well for 

 water on the site of what is now the Heathfield Hotel. At 300 feet the borers 

 met an inflammable gas ; but as they were seeking for water, and none was 

 reached, tlie borehole was cemented up and left. 



In August 1896 men employed by the same firm were at work boring a well 

 for the L. B. & S. C. Railway Company for water; at a depth of 300 feet they 

 also found an inflammable gas. But no water was reached even when another 

 ] 00 feet had been sunk. 



Three years afterwards the railway company decided to put the gas to some 

 useful purpose, and ever since the railway station has been lit with natural 

 gas. The consumption is about 1,000 cubic feet per day. 



Hearing of this very practical outcome of the second discovery, I expected 

 to hear also that explorations would be made to discover the extent of the gas-* 

 bearing area. But finding that no further steps were taken, I communicated with 

 some American friends, who aslced me to take steps. 



I located positions for six exploratory boreholes to be made ; we commenced 

 boring, and in all of the boreholes we have struolc gas, .at levels \ arying from 

 300 to 400 feet from the surface, the farthest borehole of the six beii'io- distant 

 some 1,200 yards from the railway station. 



These six boreholes are started in the geological formation known as the- 

 Hastings bed, which — in the Heathfield district — lies some 400 feet geologically 



1903. 3 E 



