May i6, 1878] 



NATURE 



75 



street pipes in lieu of wooden ones were introduced a' 

 the end of the last century, and the plan of filtration in 

 1829 by the Chelsea Company. 



The tidal portion of the Thames at Hammersmith and 

 Kew afforded a supply only thirty years ago, until the com- 

 panies were at length compelled to take their supplies from 

 above Teddington Weir, so as to be out of tidal influence. 

 Five London Water Companies have the power to draw 

 about 110,000,000 gallons per day from the river; its 

 minimum flow during the minimum month of 'dry years is 

 350,000,000 gallons per diem. Mr. Beardmore estimates 

 the amount of rainfall run off the Thames basin above 

 Kingston from 1850 to 1868, to give a mean annual rate 

 of 7*83 inches, while the mean rainfall at Oxford was 

 26 "08, the rest of the rainfall being evaporated, or absorbed 

 by vegetation. The head waters of the Thames are main- 

 tained by springs of the oolites, but these lose their volume 

 after drought, the dry-weather flow of the river being 

 maintained by the deep-seated springs of the chalk, which 

 occupies an area in the Thames Basin, above Kingston, 

 of 1,047 square miles, and has, according to Mr. Beard- 

 more, a storing capacity of sixteen months. 



Large numbers of wells have been sunk in the metro- 

 politan area during the present century, into the Thanet 

 Sands, underlying the London Clay; as these by pumping 

 became exhausted, the chalk was penetrated, and the 

 rainfall which is absorbed in the Hertfordshire and Surrey 

 Hills, and flows down the dip planes of the strata under 

 the London clay of the Thames Basin, was pumped up 

 by the brewers and other large consumers. The constant 

 tax, however, on this supply has caused a steady and 

 increasing depression in the level to which the water will 

 rise, and has necessitated in many instances the lowering 

 of the pumping machinery in the metropolis. 



Eighteen million gallons ^ daily of water of the River Lea 

 that would have naturally gravitated towards London is 

 intercepted by the New River Company, who pump their 

 chalk wells most, when the River Lea is driest, and thus 

 draw upon the deeper springs, which would not in 

 ordinary course have reached the surface in that area. 



Following the example of some 100 or more provincial 

 towns that have acquired the control of their own water- 

 works, the Metropolitan Board of Works have laid before 

 Parliament a bill to acquire the rights of the whole of 

 the London water companies, which, at twenty years' 

 purchase, are valued at fifteen million pounds, an amount 

 steadily increasing, and have coupled it with another 

 bill, to give effect to Messrs. Bramwell and Easton's pro- 

 posal to sink chalk wells for a separate supply for drink- 

 ing purposes. Influenced probably by the enormous cost 

 of the one scheme, and the inconvenience attendant on 

 the laying of 2,600 miles of new pipes in the other, the 

 proposals are not supported by the ratepayers, who appear 

 to consider "living organisms" in the water now sup- 

 plied to them a minor evil. The "purchase bill" is now, 

 however, abandoned for this session, and the "well 

 scheme" will probably rest for the present. 



An extension of Mr. Bateman's project for bringing 

 the Vyrnwy and other head waters of the Severn to the 

 metropolis, has recently been suggested for the future 

 requirements of Liverpool, sixty miles distant ; the 

 watersheds between the Mersey, Dee, and Severn basins 

 are very low, so that little tunnelling would be required. 

 The scheme is stated by Mr. Hugh Williams, Avho 

 suggested it, to be capable of yielding, if required, no 

 less than 193,000,000 gallons of water daily, after allow- 

 ing for compensation, a quantity which would suffice for 

 the wants of six millions of our population, and could 

 not fail to have a salutary influence on the floods of the 

 Severn. 



Charles E. De Range 



'The New River also receives 3} million gallons daily from the Chad well 

 Spring, and the water obtained from various wells in the chalk. ■ 



NOTES 



Since our last number appeared American science has 

 sustained a loss which will be universally deplored. Prof. 

 Joseph Henry, the Director of the Smithsonian Institution, 

 whose labours for the progress of science, all the world over, 

 have been increasing, is no more. We shall take an early 

 opportunity of referring to his long-contuiued labours for the 

 furtherance of natural knowledge among men. 



We understand that Mr. E. Roberts, of the Nautical Almanac 

 office, has been requested by the India office to construct for use in 

 India a self-acting tide-calculating machine. It wiU be designed 

 not only to predict the tides at open- coast stations, but also 

 river and shallow -water tides. It will be a great improvement 

 on the tide-calculating machine at South Kensington (now tem- 

 porarily at the Paris Exhibition), inasmuch as the tides caused 

 by the smaller lunar perturbations will be included. Each com- 

 ponent will be fitted with a slide, so that no error ^\'ill be caused 

 from the excentricity of the pullies. The ordinates of the curves 

 traced by the machine bemg as much as eighteen inches, the use 

 of the slides is imperative. Mr. Roberts has calculated new 

 numbers to represent the periods of the many components, and 

 with such success, that the actual error of any one component, 

 after a run representing a year's predictions, will not exceed the 

 limit of error of setting the component at the commencement. 

 The machine will be fitted with self -regulating driving-gear, 

 so that it can be set at the close of the day and the whole 

 year's curves be ready for reading off by the next morning. The 

 machine is expected to be finished towards the end of the year. 

 Now that the immense labour (the only objection raised against 

 the employment of tidal predictions by harmonic analysis) is 

 superseded, it is to be hoped that the Admiralty will avail them- 

 selves of an instrument, the results of which are so vastly superior 

 to those now obtained with considerable labour by actual 

 computation. 



Prof. Huxley has. been elected a corresponding Fellow of 

 the Royal Academy of Rome, in the Department of Natural 

 History. 



We learn that the following gentlemen, all highly distin- 

 guished for their numerous original researches and published 

 memoirs on physiological and systematic botany, have recently 

 been elected foreign members of the Linnean Society of London : 

 — viz.. Prof. Teodoro Caruel, of Pisa, Dr. Ernest Cosson, of 

 Paris ; Dr. George Engelman, of St. Louis, Missouri, U.S. ; 

 Prof. Eduard Fenzl, of Vienna; and Prof. Jidius Sachs, of 

 Wiirzburg. 



On April 29 a monument, in memory of the great physicist, 

 Alessandro Volta, was unveiled at Pavia. Most of the Italian 

 Universities, and several foreign scientific societies had sent 

 deputies to Pavia University for this event. The monument is a 

 masterpiece of the sculptor Tantardini of Milan. The ceremony 

 of unveiling was followed by a dignified celebration at the 

 University, and upon that occasion the following gentlemen 

 were elected honorary doctors of the scientific faculty : Profes- 

 sors Clerk Maxwell (Cambridge) and Sir W. Thomson (Glas- 

 gow) ; M. Dumas (Paris), Dr. W. E. Weber (Leipzig) ; Professors 

 Bunsen (Heidelberg) and Helmholtz (Berlin), Dr. F. H. Neumann 

 (Koenigsberg), and Dr. P. Riess (Berlin). 



The death is announced of Roberto de Visiani, " the Nestor 

 of Italian botanists," Professor of Botany at Padua, aged 

 seventy-eight. 



We notice the death m Berlin on April 22 of the well-known 

 astronomer Prof. Wolfers. For many years he was connected 

 with the Berlin Observatory, and, as editor of the Jahrbuch 

 issued from this institution, he has for the past forty years 

 rendered services of the greatest value to astronomy. His re- 



