It is to be hoped that, before the next number of this Review appears, we shall have welcomed back the victors with rejoicing, tempered, however, with sorrow that one out of this brave little band has been left behind in the lone ocean-a congenial resting-place, it may be, seeing that it was the scene of his late labours. "Whom the gods love, die young."

EXPLANATION OF PLATE CXXIX.*

"Es giebt ein vollendetes organisches Leben im unsichtbar kleinen Raume, welches die Grösse des Grossen in der Natur unabsehbar erhebt."-Ehrenberg, Die Infusionsthierchen." 1838.

FIG. 1. Globigerina, with the radiating processes entire. From the Challenger soundings. After Pl. I. vol. xxiii. "Proc. Royal Soc." It is evident that when this figure was drawn the investing envelope of sarcode, mentioned by Professor Wyville Thomson in his letter to Professor Huxley ("Nature," Aug. 19, 1875), had not yet been discovered.

FIG. 2. A "Cyatholith," from the Atlantic mud, magnified 1,200 diameters. After fig. 4, c, i, Pl. IV. "Quart. Journ. Micr. Sci.," New Series, 1868.

FIG. 3. A "Cyatholith," from the chalk of Sussex, magnified to a similar degree. Ibid. fig. 5, b, c.

760

FIG. 4. A cluster of " Coccospheres," of the loose type, about th inch in diameter, from the Atlantic mud. Ibid. fig. 7, d, and p. 209. FIGS. 5 and 6. "Rhabdospheres" (Murray), from the Challenger soundings. After figs. 3 and 4, Pl. III. vol. xxiii. "Proc. Royal Soc." FIG. 7. "The new Diatom." Found a little to the North of the Heard Islands. Ibid. fig. 5.

* The woodcuts have been kindly lent by Messrs. Macmillan & Co.

WATER SUPPLY AND PUBLIC HEALTH.

By W. TOPLEY, F.G.S.,

Assoc. INST. C.E. GEOLOGICAL SURVEY OF ENGLAND AND WALES.

IN

N the year 1868 a Commission was appointed to inquire into the best means of preventing the pollution of rivers, with special reference to the disposal of sewage, to questions relating to water supply, and the public health generally. Five Reports have appeared during the last seven years; these dealt with the pollution of certain selected rivers, the question of water supply being only incidentally referred to. In the sixth and final Report the Commissioners devote their attention exclusively to the "Domestic Water Supply of Great Britain."

The names of Dr. Frankland and Mr. J. C. Morton are sufficient guarantee for the accuracy of the information given in the Report. But in this complicated question names alone, however eminent, are not sufficient to stamp with unquestioned authority all opinions and inferences; and we do not doubt that some conclusions contained in the Report will be stoutly denied by authorities equally eminent. That the work, so far as data are concerned, has been thoroughly done, will be evident from the fact that more than 2,000 analyses of water have been made. These have all been made on a definite plan, and are arranged as systematically as could conveniently be done. The Commissioners state that "water has been followed through the complete cycle of its migrations; it has been caught as it descended from the clouds soon after its condensation from colourless and invisible vapour, collected as it flowed in streams after washing the surfaces upon which it fell, examined after it had penetrated to various depths through

"Sixth Report of the Commissioners appointed in 1868 to inquire into the Pollution of Rivers." [By Dr. E. Frankland and J. C. Morton.] Folio. Lond. 1874. Pp. xi. 525; Maps and Plans. (Although dated 1874, the Report was not issued till late in 1875.)

different geological strata, and finally it has been investigated after it had become part of the great mass of the ocean.

The Report is accompanied by four maps and several plans and diagrams. One map, by Mr. C. J. Symons, shows the rainfall of the British Isles. Another is geological; this is prepared by Mr. E. Best, chiefly from the maps of the Geological Survey.

In 1867 a Royal Commission was appointed to inquire into the question of water supply, with especial reference to the metropolis; this Commission issued its Report in 1869. The two Commissions thus traversed to a great extent the same ground, and their Reports will serve as a mine of information on this subject for years to come.

During 1844 and 1845 a series of Reports were issued on the "Health of Towns," which deserve to be better known than they are; but, unfortunately, it is often the fate of "blue books" to be forgotten soon after publication. These Reports are worthy of attention even now for the topographical information which they frequently contain; still more are they worthy of study as denoting the immense advance of sanitary measures during the last thirty years. Bad as matters now are in many large towns, they were infinitely worse then; and sanitary reformers may well take heart at the contrast. Water supply was then one of the most important subjects which engaged the attention of the reporters. Recourse was subsequently often had to neighbouring rivers or streams for a regular supply under efficient control, and for a time all went well. towns increased in size, systematic sewerage was introduced, and the rivers were rapidly fouled. And now the problem of how to supply pure water to many overcrowded towns is again awaiting solution.

But the

But, in dealing with this question, it is important to bear in mind that the problem is no longer limited to the larger towns and the great centres of industry. Here there are wealth and public spirit, and sooner or later such places will provide for themselves. But, unless carefully watched, such provision is often made at the expense of smaller towns and villages. One great point in future legislation should be to secure an adequate supply of water for entire districts, especially for those situated within the drainage area from which the supply is drawn.

A study of a good geological map shows that the old village settlements cluster along water-bearing strata; generally they are on or near the edge of porous beds, into which the rain partly sinks as it falls, to be again thrown out as springs at the edge of an impervious bed. There were doubtless other reasons for selecting these sites; land which absorbs water has a dry soil, suited alike for dwellings and arable culture, in days

when draining was unknown. The neighbouring heavier lands were then generally thickly wooded.

Many interesting questions are associated with this inquiry. We can often trace out the earliest settlements of a district along the outcrops of certain strata yielding the best soil and an abundant supply of water; that they are the earliest settlements is evident from an examination of the relations of their parish or township boundaries to the neighbouring hill ranges, and sometimes also from a study of their names.

*

In the course of thirteen centuries many changes have been wrought on the physical features of the country. Forests have all but disappeared from the plains and the hill slopes, fens and morasses have been drained. As a consequence partly of these changes many springs which once ran strongly now give but a short and inconstant supply; streams are lessened in flow, and are often nearly dried up in summer. The climate has become drier; but whether the actual amount of rainfall has diminished during this period, and if so how far this change is due to man's influence, are questions at present undecided.

One result of modern agricultural drainage has been to bring the rainwater quickly down into the brooks, and hence the rivers have risen into flood more quickly than before. That the water does descend more quickly after rain than it did some years back, is a matter of common observation amongst anglers and farmers; they also remark that the rivers more rapidly regain their ordinary level than they used to do. These observers, in common with nearly all agricultural authors, explain these facts by the prevalence of drainage. Mr. R. Rawlinson and the Rev. J. C. Clutterbuck, however, deny this; † and the former states that the object of drainage being to carry the water down through the soil, the result must be to retard the flow of water.

But whatever may be the result of under-draining cultivated lands, there can be no doubt of the effect of trenching the upland pastures, moors, and peat bogs, amongst which most of the northern rivers take their rise. Peat acts like a sponge in absorbing the rainfall; the surface of some bogs often rise very considerably when distended by water, and at times when over-strained the surface bursts and considerable damage ensues. But this is only the case with what are termed "flowes" or shaking bogs, which generally occur at low levels; and it rarely happens with the peat bogs of hill districts.

I have discussed this question in a paper "On the Relation of the Parish Boundaries in the South-East of England to great Physical Features, particularly to the Chalk Escarpment."-" Journ. Anthrop. Inst." vol. iii. p. 32, 1873.)

† See their letters in the "Times" for November 16 and 19, 1875. VOL. XV.-NO. LVIII.

D

These high peat bogs are reservoirs of water, which they collect in winter and yield gradually in summer. They generally lie at too high a level to be cultivated for grass or corn, but they are capable of some improvement as rough upland pasture. This improvement is often secured by deeply trenching the bogs in various directions; the water then drains off, the soil becomes drier and affords feed for sheep. This process is largely going on, and if continued will, in the course of only a few years, make its results seriously felt on the summer and autumn flow of the rivers in the north-east of England. Such results will be less felt, indeed may be comparatively unimportant, in most rivers on the western side of the great central watershed of England; for there the rainfall is much greater, and the periods of drought are shorter. But on the eastern side of the watershed it is simply equivalent to destroying a large number of natural "compensation reservoirs," which at present serve to diminish the winter floods and to augment the summer flow. The additional value conferred on the uninhabited upland moors is but small; the loss to the populous cultivated lowlands is immense.

The late floods have once more made evident the importance of storing the surplus rainfall for summer use. This, with more embankments and fewer weirs, will lessen the floods. Some day probably all this will be done, but at enormous expense. Meanwhile it might be well to see to the preservation of those reservoirs which Nature has herself provided.

A supply of water and the disposal of sewage are two of the most difficult problems of modern times; whilst either, taken alone, would in many cases be comparatively easy. The readiest mode of getting rid of sewage is to pour it into the rivers and streams; but this fouls the natural source of water supply. Pollution of rivers by such means will in time be largely checked; we shall some day discover that sewage is too valuable to be thrown away. But even if the utilisation of sewage should not prove actually profitable, it will be found advantageous to spend public money on this, and thus to prevent the fouling of rivers to the extent now practised and each year increasing. By these and other means the pollution of rivers may be greatly reduced, but it can never be wholly prevented; and it is useless to look for a supply of water for drinking purposes from rivers which traverse manufacturing or populous districts.

"Doctors disagree" in many things of great moment to the public health, but in none is this disagreement more to be regretted than in questions relating to water supply. Complete accord as to opinions and inferences is not to be expected, but we may certainly hope for more agreement as to facts and as to the mode in which these facts are published. Carefully prepared