May \6, 1878] 



NATURE 



time, as presenting a condensed criticism of all that had 

 been effected in this direction ; this paper was originally 

 read to the council, in support of Bessel's claim to the 

 gold medal for "his assumed discovery of the parallax of 

 the remarkable star 6i Cygni." In 1845 Mr. Main pro- 

 cured the reduction of the numerous sextant observations 

 of the great comet of 1843, the results of which were 

 presented in a memoir read in January, 1846; but they 

 did not justify, in point of precision, the time and trouble 

 ■which had been expended upon them. In a paper read 

 March, 1849, Mr. Main gave his deductions on the 

 ellipticity and form of the planet Saturn, from measures 

 at the Royal Observatory, showing that there is not, as 

 was suspected by Sir William Herschel, any sensible 

 deviation from a perfect ellipse. In April, 1856, he made 

 a communication on "the values of the diameters of the 

 planets having measurable discs," embodying observations 

 with a double-image micrometer, extending from 1840 to 

 1852. His subsequent contributions to the same memoirs 

 are (i) "On the Value of the Constant of Refraction" 

 (1857), (2) "On the Proper Motions of the Stars of the 

 Greenwich Catalogue of 1576 Stars for 1850" (1858), 

 (3) "On the Value of the Constant of Aberration" (i860). 

 Mr. Main successively filled the offices of Secretary and 

 President of the Royal Astronomical Society. 



As Radclifife Observer Mr. Main has most conspicuously 

 maintained for the Oxford establishment the high repu- 

 tation with which it was left by his energetic and respected 

 predecessor, Mr. Johnson. The successive volumes of 

 observations have appeared with marked regularity, Mr. 

 Main himself taking a much more actire part in the 

 routine computations than is usual for the director of an 

 observatory, with the view of insuring with his compara- 

 tively small force this desirable result. Of the great 

 value attaching to the RadclifFe observations it is unneces- 

 sary to speak here. We will only express the hope that 

 the future conduct of the Institution may render as valu- 

 able services to practical astronomy as in the hands of 

 Johnson and Main it has done in the past. 



THE NATIONAL WATER SUPPLY 



"VTEXT to a Conference of European powers delibe- 

 J-^ _ rating on the fate of nations, it is difficult to 

 imagine a Congress which may possibly more largely 

 affect the welfare, health, and life of the people, than 

 that to be held at the Society of Arts next week, on the 

 subject of Water Supply. 



The Congress is called at the instigation of His Royal 

 Highness the Prince of Wales, to consider his proposition 

 "how far the great natural resources of the kingdom 

 might by some large and comprehensive scheme of a 

 national character, adapted to the varying specialties 

 and wants of districts, be turned to account not merely 

 of a few large centres of population but for the advantage 

 of the nation at large." 



To inquire into these resources has been one of the 

 objects of various Royal Commissions, which, though 

 conducted with great ability, a lavish expenditure of 

 time, and successful in collecting a large amount of very 

 valuable information, have all failed to recommend how 

 these bountiful stores of water can be made available. 

 They found in the words of the Rivers' Pollution Com- 

 missioners "that an inquiry into the water supply of 

 provincial towns must be one of great magnitude, in- 

 volving a large amount of statistical and topographical 

 investigation over the whole kingdom." 



The Duke of Richmond's Commission, 1868-9, found 

 it impossible, without further powers to carry out the 

 inquiry, but they express their decided opinion " that the 

 Legislature should jealously watch any proposal for a 

 town taking water from a gathering ground at a distance 

 from it, lest by so doing it may deprive other places 

 nearer to such gathering ground of their natural source 



of supply ; " and further, " that when any town or district 

 is supplied by a line of conduit from a distance provision 

 ought to be made for the supply of all places along such 

 a line." This last suggestion has been adopted by the 

 Select Committee of the House of Commons, lately 

 ordered to "report upon the present sufficiency of the 

 water supply of Manchester and its neighbourhood, and 

 of any other source available for such supply," who 

 recommend that the towns along the route of the pro- 

 posed aqueduct from Thirlmere to Manchester be allowed 

 a supply, after Manchester has been provided with 

 twenty-fiv^e gallons per head. It is a source of regret 

 that this Committee did not avail themselves of their full 

 powers to inquire into all the means existing of supplying 

 Manchester, as even should the Thirlmere scheme have 

 proved the best, the information gained might have been 

 useful to other districts. For though it is advisable that 

 the inhabitants of Manchester, being accustomed to soft 

 water, should continue to receive it, hard would probably 

 be found equally wholesome, if pure, to those populations 

 they propose to supply that are not at present using soft 

 water. ^.,7 



Three points will probably be uppermost at the Con- 

 gress — (i) Evidence to show the stores of water available ; 

 (2) How far the existing water legislation requires amend- 

 ment, so as to give cheaper and quicker water powers to 

 sanitary authorities than at present ; and (3) How far it is 

 advisable to have a National Water Supply Survey of the 

 whole kingdom in connection with the Department of 

 Health, technically known as the Local Government 

 Board. 



Looking to the fact that the labours of the" various 

 Royal Commissions and Select Committees have failed 

 to recommend a scheme of provincial water supply, it is 

 perhaps too much to hope that the present Congress will 

 succeed ; but when it is remembered that these failures 

 prove the absolute necessity of personal examination of 

 each district, and finding for each a scheme suited to its 

 special requirements, we may look forward to this expe- 

 rience being utilised, and a scheme elaborated in which 

 a scientific inspection of the country will play a principal 

 part. 



At this juncture it may not be without interest to 

 glance at the present sources of supply of some of our 

 great centres of population, and the means that are 

 being taken to increase it. 



The older palaeozoic rocks forming the elevated tracts 

 of the English Lake District, the Scottish and Welsh 

 Hills, and Dartmoor, all of which are practically imper- 

 meable to water, lie west of a line ranging through the 

 mouth of the Exe on the south coast, to the mouth of the 

 Tyne on the north-east coast, and it is west of this line 

 that the largest rainfall is received, ranging from 40 to 

 150 inches per annum. The rapid slopes and imper- 

 meable nature of the ground on which it falls cause it to be 

 nearly all carried off in floods often of the most destruc- 

 tive character, and exceeding the dry weather flow 500 

 and even 1,000 times ; the floods in the Silurian mountain 

 districts amounting, according to Mr. Bateman, to a 

 volume of 200 to 500 cubic feet of water per, second 

 derived from each 1,000 acres of area, while in dry 

 weather the water given off by peat-mosses, and the 

 unimportant springs found in such districts, will only 

 amount to from one-fourth to three-fourths of a cubic foot 

 per second. 



The enormous volumes of pure water which run off 

 the Westmoreland and Cumberland Mountains are stored 

 to a certain extent in the numerous lakes which traverse 

 that district, occupying true rock basins and often attaining 

 a greater depth than the English Channel between Folke- 

 stone and Boulogne. Engineers have from time to time 

 proposed them as sources of water supply for the crowded 

 population of Lancashire, and even for the metropolis, 

 and at length the House of Commons has assented to Mr. 



