페이지 이미지

Munee Range.* On this lake floated the icebergs brought down by the rivers, drifting gradually to the south, and finally grounding near the Salt-Range or averted by it. Thus we see between Jubbee and Nikkee large erratic blocks, being porphyry, resting on the top of the old alluvium; and we find similar but smaller blocks imbedded in horizontal taluses of debris which have been piled up in horizontal layers against the bills of Marec on the Indus. These blocks are not water-worn, but present either flattened or scratched surfaces; the ground all over that district is covered with boulders of porphyry, greenstone, felstonc, &c. but these boulders are well rounded and are easily traced to disintegrated beds of Miocene conglomerate. The erratic blocks are very different in appearance, and have the striking, or somewhat odd and deplaeS aspect peculiar to erraties. One of them, three miles south of the village of Thrapp, measures 6 feet 4 inches by 7 feet 4 inches and 5 feet. There are four or five smaller blocks near it, but none nrs rolled; they are all of the gneissoid porphyry of the Kaj-Nag. The largest presents the very singular appearance of having its greatest flat surface (not vertical) marked with a number of cup-like holes of various size, from 6 inches across to the size of a walnut, and from 1£ to 2 inches deep. There are from 70 to 75 of these cups. They resemble wide rounded holes or cups, as water would make by dropping. Whether these cups are a glacial effect, or have been made by a race of men for some unknown purpose, is, what I am unable to decide. I am inclined to the first hypothesis.


Erratic blocks near Thrapp.

100. The oldest indications of Man having become an inhabitant

* Tho damming of the water behind the Salt Range and the Chitta Range was the causo of that thick deposit of silty mud now cut by ravines, which has boon the source of so much difficulty and oxpense in making the great Trunk Eoad between Jheelnm and Attok. A similar damming occurred in the Hunecpor valloy and several other localities, but to a less degree

of the Himalayas is, at present found in the Upper Lacustrine deposit of Kashmir (see note to para. 44). This deposit contains a very great many fragments of pottery, hones of goats, ami pieces of charred wood. It is much older than the Buddhist ruins of Avantipoor, aud attests the presence of man in the valley during the period which elapsed between the first and the second lake. The Buddhist ruins were not built until after the second lake had been drained. But though we may call the race of men who lived in Kashmir before the second lako historically ancient, they cannot be considered so geologically: a cowry has been found* in the deposit, and this evidence of a currency indicates at once an amount of civilization and trade far removed from the state of the primitive races.

(To he continued.)

Experimental Investigations connected with the supply of water to
Calcutta, Part III.
By D. Waldie, Esq.,

F. C. S. &c. (Continued from page 8.) [Beoeivod 1st March, 1867.] The present communication is intended to give an account of the results obtained in prosecuting the investigations indicated by the title, the first of which have already appeared in this Journal. To some of the results given in the original paper objections were raised, which were examined in a subsequent article, entitled, " Supplementary Observations, &c," these being founded on experiments made during the month of September last. Since that time the enquiry has been continued, with the view of more fully examining these objections, of supplying certain deficiencies, of correcting some errors, clearing up some obscurities, and generally rendering the enquiry more complete.

I propose also to endeavour to correct some misapprehensions which seem to have arisen, and indicate points of importance which do not

* Tho cowry was discovered by Captain Godwin-Austen while wo woro examining these lacustrine boda together. 1 Hm\ C'milaiu Ausleu dig it out of the clay with his pcukuilo.

appear to have attracted the attention that was due to them. I shall also draw my own conclusions from my results, stating at the same time with what amount of confidence they are made.

Inorganic constituents.

In the original communication, on account of an unforeseen and unexpected source of error which vitiated some of the results and therefore rendered the series incomplete, only a general view of the relative proportions of alkaline and earthly salts at tho different seasons, taken from the tables in Dr. Macnamara's Report, was given. It may be of interest to state the nature of the source of error, then only hinted at. It occurred in the case of the waters of December and February, greater part of which had been kept in green glass stoppered bottles till the month of April, which, on analysis, gave results so peculiar as to excite surprise. The same peculiarities were found in some of the analyses of the river water of Angust, in even a more marked degree. After not a little perplexity and trouble, it was ascertained that this arose from the action of the water on the glass, dissolving the glass in such proportion as altogether to vitiate the result as regards the proper constituents of the water; it having been ascertained that the silica, the alkalies, and the iiine of the glass were all added in notable proportion to the constituents of the water. It was the very large proportion of the silica obtained that first drew attention to the subject. Not being specially connected with the object of this paper, it is not necessary to notice it more particularly than to observe that there can be little doubt, but that it is due in great part to the increased activity given to the solvent action of the water by the high temperature of the climate, though indeed it occurred to a sufficiently decided degree even during the coolest months. There is probably little doubt that this circumstance has in many cases introduced error into water analyses unobserved. The analyses, in the present case so vitiated, were rejected and new ones instituted as the season gave opportunity.

For the purpose of comparison, tho most complete plan would be, to ascertain the amount of each basic and acid constituent and state these in detail. A very general, or rather the general plan hitherto followed by chemists, has been to allot the acids and bases to each other, it may be by some conventional plan or according to some favourite theory, and represent them in the state of neutral salts. And as eacb chemist may follow his own particular plan, the same analysis may be represented in very different ways. As it is simply impossible to say in what way the acids and bases are united to one another in solution, it is very much better to state them separately; and I was glad to find that Professor Dr. W. A. Miller expressed the same opinion in his paper formerly referred to. But for general purposes a full statement of each constituent is unnecessary, and when numerous samples have to be examined, is very laborious. It is generally sufficient to classify them, or select a few of the most important and characteristic constituents or properties. In the case of the mineral constituents, their total amount, the quantity of chlorine or of sulphuric acid, the proportion of earthy salts, that is, of lime and magnesia to the alkaline salts, are, singly or together, all more or less suitable according to the nature of the water to be examined. The soap test formerly noticed is a very favourite method, from the ease of its execution. I have applied it in some cases, though the nature of my enquiries led me generally to have recourse to other methods.

The following table gives a view of the constitution of the river water at the various seasons, classified in a way that seems to me very suitable for comparing different samples. The principal mineral constituents are the alkalies, potash and soda, and the earthy, lime and magnesia,—soda being the most abundant alkali, and lime the principal earthy constituent. These bases are combined with carbonic acid in much the larger proportion, and in smaller proportion with hydrochloric acid, sulphuric acid and perhaps organic acids. The carbonates of lime and magnesia are kept in solution by excess of carbonic acid, and when the water is boiled or evaporated to dry dryness, by far the greater part, indeed all except a very little of the lime and magnesia, are separated insoluble. These remarks apply to the river water proper; during the hot season, when tidal influence prevails, the constituents of scawater make their appearance; then sulphuric acid is increased a little and magnesia still more; and hydrochloric acid and soda (or chlorine and sodinm as common salt) arc largely increased in quantity.

[merged small][merged small][merged small][merged small][merged small][ocr errors][table][merged small][merged small][ocr errors][merged small]

In Table I. the alkalies are exhibited as if they were all in the state of hydrochlorates of potash and soda, or more correctly chlorides of potassinm and sodinm, chloride of sodinm or common salt being the best type of such compounds, and the one most familiar to ns, and practically most important. The earths are exhibited as if they were all in the state of carbonates of lime and magnesia, these compounds being also the most familiar ones. By this arrangement, the relativo proportion of these constituents at different seasons can be easily compared. I am not aware that this plan has been used before, but it seems to me a good one, particularly when combined with the results given in Table II.

* Silica mixed with more or less clay.

« 이전계속 »