374 



NA TURE 



\Angust 30, 1877 



rabbit, several birj':, and water-vole, complete the list of those 

 wrhich have been determined from the bones obtained in the 

 year. 



A great part of the work this year has been expended in 

 lowering the levels in chambers A and D. An adit has also been 

 cut from the fuither end of Chamber A to the end of Chamber 

 D. This part was completely filled up to the roof with several 

 beds of clay and stalagmite. These were all of earlier age than 

 the hysena bed, which was the great deposit of early pleistocene 

 age. They were almost entirely free from animal life of any 

 kind. The oniy specimens found were near the bottom of them, 

 and in one spot, consiiting of teeth of a small wolf. This, then, 

 is by far the oldest inhabitant of the cave. The presence of 

 wolf of course implies the presence of other animals. 



The Committee is now working with a view to disclosing the 

 old bed of the river which first formed the cave. 



Third Report of the Coininillec Jor Inres/igaliiis; the Ciiiiilation 

 of Underground Waters in the Nciu Red Sandstone and Permian 

 Formations of England, and the Quantity and Character of the 

 Water stipphed to various Toums and Districts from those 

 Formations, drawn up by C. E. De Kance (secretary), with 

 supplemental report by T. M. Reade. — No less than 10,000 

 square miles of England and Wales are occupied by the new 

 red sandstone and permian formations, which absorb not less 

 than ten inches of rainfall annually, and probably more where 

 the overlying drift is pervious or absent, and the sandstone 

 open and permeable. 



The Rivers Pollution Commissioners classify waters in the order 

 of their excellence, for general fitness for drinking and cooking, 

 as follows ; — 



Very palatable. 



( I. S;^ving water. 



A. Wholesome. 2. Deep well wattr. \ 



( 3. Upland surface water. ( Moderately palat- 

 i 4. Stortd rain water. ) able. 



B. Suspicious. ■ 5. .Surface water from 1 



( cultivated land. | 



I 6. River water to which \ Palatable. 



C. Dangerous. sewerage gets ac :ess. | 



( 7. Shallow well water. J 



The average amount of hardness of the water of ihe deep 

 wells of the new red sandstone tabulated by the R.ivers I'oUulion 

 Commission being I7°'g, and that of the springs no less than 

 iS'^S, the relation of hardness of water to the rate of mortali'y 

 of the persons diinking it becomes a matter of great importance. 



The Commissioners give three tables of statistics that bear 

 directly upon this point :— 



From Table I. it appears that in twenty-six towns, inhabited 

 by 1,933,524 persons supplied with water, not exceeding 5° of 

 hardness, the average death-rate was 29°'I per 1,000 per 

 annum. 



From Table II. we learn that in twenty-five towns inhabited 

 by 2,041,383 persons drinking water of more than 5°, but not 

 exceeding 10", the average death-rate was 2S'''3 per 1,000. 



Table III. gives sixty towns, with an aggregate population 

 of 2,687,846, drinking water of more than 10' of lurdness ; the 

 average death-rate was only 24''*3. 



Of the towns in Table I. none are supplied from the new red 

 or permian formations. 



In Table II. three are so supplied. 



In Table III. ten are so supplied, from which it will be 

 observed that the largest number of towns supplied with new 

 red water are found in the table with the lowest death-iate 

 and the hardest water. 



The same result is obtained if we compare towns of corre- 

 sponding populations and occupations supplied with soft waters 

 from surface areas and those supplied with deep well water in 

 the new red sandstone. Thus: — 



Per 1,000. 

 Manchester, 351,189 inhabitants, average death-rate ... 320 

 Birmingham, 343,787 ,, ,, „ ...24-4 



And again — 

 Stirling, 14279 ,, ,, ,, ,, 26'i 



Tranmere, 16,143 d >> i> ■ l8'8 



The averages are, of course, also dependent on many external 

 causes. Thu?, Greenock and Plymouth, both supplied with 

 soft water, with an equal numlxr of inhabitants have a death-iate 

 respectively of 326 and 23-3 per 1,000, due to difference of 

 density of popuhtion, Greenpck only having one house for every 



twenty-eight people. And again, Liverpool and Birkenhead, 

 both supplied with moderately hard water in the one, an old and 

 densely-populstel town with a .site saturated with what is in- 

 jurious to he.ilth, the death-rate is 31 per 1,000, while Birken- 

 head, a new town on an open site with wide streets, has a death- 

 rate of only 24 per thousand, though mainly inhabited by a poor 

 and struggling class of perF.ons. 



Still it i; worthy of note that the five inland manufacturing 

 towns with the lowest death-rate are all supplied with hard 

 water, anl all from the new red sandstone. 



Average 



144,981 



25-5 



.'Vnd acain the average death-rate of twelve inland non-manu- 

 facturing towns supplied v.'ith soft water was 260 per 1,000, 

 while that of twenty simihar towns supplied with hard water 

 was only 23 '2. 



When, however, the mortality of the districts, including the 

 principal English watering places, is compared, there appears 

 to be little variation in the death-rate, whether the population be 

 supplied with soft, moderate, or hard water, so that it may be 

 safely concluded that where sanitary conditions prevail with 

 equal uniformity, the rate of mortality is practically uninfluenced 

 by tlie degree of hardness of the water drunk, and the Rivets 

 Pollution Commission are of opinion that soft and hard waters, 

 if equally free from deleterious organic substances, are equally 

 wholesome. 



The Committee are of opinion that it is desirable that they 

 shovdd contiiiueto inquire into areas where new red and permian 

 waters might be obtained by means of deep wells. Looking to the 

 national importance of utilising the underground waters of England, 

 it is deiir.ible that the sphere of this inquiry should be extended 

 so as to include the oolites, which are often not made available 

 (or the supply of the population living upon them until the water 

 is hopelessly polluted with sewage, fhe result of their labours, 

 since the formation of the Committee, has been to prove that 

 there is an available supply of water from the new led sandstone 

 and permian of England of not less than a billion and a-half of 

 gallons of water, the qu.ilily of which is lemarkably free from 

 organic impurity, and the hardness of which does not in the least 

 appear to affect the he.ilth of the population at present taking 

 their supply from it. The death-rate of this area compares well 

 with the best soft-water distiicls. 



Mr. J. Mellard Reade, C.E., F.G.S., added a special report On 

 the South-JVest Lancashire Wells, in which he analysed the infor- 

 mation he had obtained for the Committee through the printed 

 forms of inquiry, supplemented by further inquiries which had 

 .luggestfd themselves to him. For the purposes of comparison 

 Mr. Reade selected three nuclei or centres, about which the 

 most important systems of wells are grouped, viz., Liverpool, 

 Birkenhead, and Widnes, and illustrated them by maps and 

 vertical sections showing the relative water-levels reduced to a 

 common datum. 



The President thought it important to note the influence of 

 heavy and long-continued rain in relation to absorption by rocks. 

 When r.iin lasts only a short time, even if it were very heavy, 

 only a little was absorbed ; hut if the rainfall were spread over 

 a longer time, a larger proportion would sink into the rocks. 

 M. Lebour tk-scribed the method adopted by the French engi- 

 neers for representing the underground water-contours on maps, 

 there being also linos showing t'ne strike of the rocks ; he com- 

 mended this method to the consideration of the Committee. 



SECTION A. — Mathematical and Physical. 



On the Relati-M A f patent Brightness of Objects in Binocular 

 and Monccular Vision, by Silvanus P. Thompson, B. Sc. — It is 

 a common idea that objects appear brighter when seen with the 

 two eyes than with one. There appear, however, to be excep- 

 tions to this statement. The following is a methcd of submitting 

 the question to photometric measurement : — The comparisoHT 



