and Siilterranean Water Storage. 69 



land, and in the Isle of Mull in Scotland. The west coast of 

 Ireland and the northernmost islands of Scotland come next ; 

 the south of Ireland, the western counties of Eng^land, and the 

 coast of Wales succeed. The middle of England is much behind, 

 and the east coast far more so, as will be evident from the annexed 

 diagram. The neighbourhood of London, though below the 

 general average, is by no means so dry as the counties of Norfolk, 

 Cambridgeshire, and Suffolk. With few exceptions, the various 

 stations agree in showing that local rainfalls have some relation 

 to the average of the whole countr}'. 



The quantity and distribution of rain being dependent to a 

 very great extent on the peculiar physical features and the con- 

 dition of the surface of the country, the inquiry naturally suggests 

 itself whether there has been any modification of these features 

 in England within the last half century. During this time, 

 although no great changes have been wrought except in the 

 drying up of a few large sheets of water, much has been done to 

 the surface by draining and cultivating the land, and there has 

 also been a large increase of population, a vast development 

 of manufactures, and a consumption of fuel steadily increasing, 

 and now amounting to almost eighty millions of tons per annum. 



Some years ago (in 1859) j\Ir. Glaisher suggested that the 

 mean annual rainfall in the neighbourhood of London was appa- 

 rently diminishing in quantity. This idea was met by objections 

 expressed forcibly enough by Mr. G. J. Symonds, and published 

 in the ' Proceedings of the British Meteorological Society ' for 

 January, 1863. The conclusion had previously been opposed 

 by Mr. Jamieson, who, in an Essay referring chiefly to Scotland, 

 but including a wider area, set forth that a small decrease at one 

 station was met by a corresponding increase in another, and that 

 the compensation was complete. Arago had previously stated 

 that in the neighbourhood of Paris there had been no appreciable 

 change for 130 years; but the records of the rainfall made so 

 long ago are hardly to be trusted. Many years must elapse 

 before the accurate rain-gauges now used at many stations in 

 the British islands and the Continent will have yielded a suffi- 

 cient collection of observations to enable us to obtain from them 

 such information as may settle the question finally, one way or 

 the other, for all parts of England. 



The rain observations made at Greenwich are, beyond doubt, 

 the most to be depended upon of any on record. Up to the 

 present time (September, 1865) they include a period of fifty 

 years, commencing January 1, 1815, and ending December 31, 

 1864 ; and a careful study of them affords a reliable basis on 

 which an opinion can be founded. Let us endeavour to deter- 

 mine the facts deducible from these records. 



