I02 



NATURE 



[May 29, 1879 



average about ten inches of rainfall a year, which, if all ' 

 yielded up to wells, would give a daily average supply of 

 400,000 gallons per square mile, and he further shows that 

 the larger area of these permeable formations lies east of 

 the great water-shed, dividing England diagonally, and 

 separating the Severn and Trent basins on the one side, 

 from those of the Thames, east coast streams, Witham 

 and Ouse on the other, the only important previous for- 

 mation west of this boundary being the permian and 

 new red sandstones. The latter occupies an area of 

 3,190 square miles. 



This different disposition of the permeable and im- 

 permeable strata in England, at once explains how it is 

 that the dry-weather flow of rivers like the Thames, 

 draining a basin largely consisting of permeable strata, 

 differs so remarkably in volume from rivers like the Severn, 

 mainly occupied by impermeable silurian rocks and 

 triassic marls, and the necessity is at once apparent of 

 there being a central authority, taking cognisance of all 

 matters bearing on water questions, and assisting parlia- 

 ment in giving or withholding to any corporation or 

 district the water rights of any area to which they may lay 

 claim. Thus, in the case of Liverpool, it is proposed to 

 take from the sources of the Severn, a quantity of not less 

 than 52,000,000 gallons a day, while Mr. Hawksley, in 

 evidence before the Royal Rivers Commission, gives the 

 driest weather flow, so low down the Severn as Tewkes- 

 bury, as only 90,000,000 gallons per day. With a margin 

 so small, it is obvious that the maintaining of a sufficient 

 volume of water for navigation, fisheries, and other pur- 

 poses, is of national importance, and should be the 

 subject of imperial care. 



The basis of all calculations of the body of water 

 available for gravitation purposes must of necessity be 

 an accurate record over numerous localities of the amount 

 of rainfall, and it is a matter of regret that the work 

 carried out by Mr. G. T. Symons is not incorporated with 

 the Meteorological Department of the Government. In 

 1865 the British Association appointed a Committee 

 to assist Mr. Symons in developing the system of regis- 

 tration ; the total number of stations now at work exceed 

 2,000, and the correspondence with these observers, the 

 verification of their instruments and codification of their 

 observations necessarily incur a large amount of expendi- 

 ture. The British Association, after many years' support 

 of the work, feeUng it their duty rather to initiate than 

 permanently subsidise investigations, have at length dis- 

 continued their grant, and the only sources with which 

 this work of national importance to the country can be 

 carried out by Mr. Symons are voluntary subscriptions 

 and the profits on the annual sale of the volume of 

 " British Rainfall." We trust that one result of the 

 Congress may be to place this work on a more permanent 

 and satisfactory basis, and also that the Ordnance or 

 Geological Survey be charged with the gauging of the 

 chief streams of the country, so that data may be fur- 

 nished for really estimating what amount of rainfall at 

 once runs off in impermeable districts, and how much is 

 .-ibsorbed in permeable districts, without which all cal- 

 culations as to probable yield are to a great extent 

 hypothetical. 



It is the fashion in some quarters to abuse the Local 

 Government Board, but when it is realised that they have 

 no authority given them by legislation to survey the 

 country, seek out abuses, suggest and compel improve- 

 ments, — until they are called to inspect often by the au- 

 thorities who have allowed abuses to devastate a particu- 

 lar district, — we think that those who read their annual 

 report of work will give them the greatest credit for the 

 industry and ability with which, often at much personal 

 discomfort, they track not only the fever-germs to 

 their source, but confront the ignoranc and obstinacy 

 of the small local authorities. We hoepe that the ac- 

 tion of the Society of Arts, in bringing these matters 



prominently before the country may lead to the scope of 

 the Local Government Board being so enlarged, their 

 staff' increased, and their sources of information widened, 

 that they may become a Department of Health, ever ready 

 not merely to find out the cause of disease, but to prevent 

 the possibility of its occurrence. Towards this end, in 

 rousing public opinion to the exigencies of the question, 

 these congresses cannot be, perhaps, too highly valued. 

 Already out of the congress held this year, a National 

 Water Supply Exhibition has been inaugurated at the 

 Royal Aquarium, which cannot but tend to popularise the 

 subject, and if it should be possible to find the Exhibition 

 a permanent home, at the South Kensington Museum, it 

 would add an important factor to the already high 

 educational value of that institution. Should a wider 

 knowledge of these subjects become general, and the 

 government legislate in the direction suggested by the 

 Society, it will be felt that its President, the Prince of 

 Wales, in first bringing the subject prominently before 

 the Society, and in lately placing it before the Premier, 

 will have been instrumental in bringing about the once 

 almost Utopian hope of Charles Dickens, in his preface 

 to the Pickwick Papers, that the time will come when " a 

 few petty boards and bodies — less than drops in the great 

 ocean of humanity which roars around them — are not for 

 ever to loose fever and consumption on God's creatures, at 

 their will, or always to keep their jobbing little fiddles 

 going for a Dance of Death." 



THE A UDIOME TER 



ALREADY have experiments of the greatest practical 

 value been made with the wonderful invention of 

 Prof. Hughes described in our last number. Dr. B. W. 

 Richardson has been applying it in two ways : as an 

 Audiometer for the measurement of hearing, and a 

 Sphygmophone for measuring the pulse. Both applica- 

 tions were described at the last meeting of the Royal 

 Society. 



The audiometer, as it had been used, was shown to the 

 Society. It consists of two Leclanchd's cells for the 

 battery, a new and simple microphonic key connected 

 with the cells and with two fixed primary coils, and a 

 secondary or induction coil, the terminals of which are 

 attached to a telephone. The induction coil moves on a 

 bar between the two fixed coils, and the bar is graduated 

 into 200 parts, by which the readings of sound are taken. 

 The graduated scale is divided into 20 centims., and each 

 of these parts is subdivided into 10, so that the hearing 

 maybe tested from the maximum of 200 units to o" — zero. 

 The fixed coil on the right hand contains 6 metres of 

 wire; the fixed coil on the left hand contains 100 metres. 

 By this means a long scale from the left hand coil is 

 produced. The secondary coil contains 100 metres of 

 wire. 



In using the instrument, the induction coil is moved 

 along the scale from or towards the larger primary, as 

 may be required, and the degrees or units of sound are 

 read from the figures on the scale, the sound being made 

 by the movement of the microphonic key between the 

 battery and the primary coils. 



The instrument may be considered to afford the most 

 satisfactory means for testing the hearing power of all 

 persons who can define a sound. The range of sound is 

 sufficient at the maximum — 200°— for every one who is 

 not absolutely deaf ; 0°, or zero, is a point of positive 

 silence from the instrument, or rather from the sound 

 which it produces through the telephone. 



One of the first facts learned with the audiometer is the 

 suddenness with which the sound is lost to those who are 

 listening. The sound is abruptly lost within a range of 

 2°; that is, within one-hundredth part of the entire scale. 

 This is the case with those who are very deaf as well a& 

 with those who hear readily. 



