I would remark that No. 13 is a weathered specimen, the surface of which is glossed over much as if it had been polished with black lead; and I observed that wherever the sandstone was glossed in this way, from exposure to the water or weather, in that locality there were coal-mines. I am told that this effect is probably due to the iron contained in the rock itself. Sz'chuan and its Cross Ranges.-At Wan the character of the Yang-tsze changes. It widens considerably, and the hills (see narrative and chart), receding from its immediate banks, give to the country a more open appearance. Extensive shingle-flats exist, and these are worked for gold.* On examination in England a very small quantity of gold has been found in the sand gathered by us, which perfectly agrees with the information we obtained on the spot, that the yield is so small as to make the labour hardly remunerative. This sand is silicious; and Mr. Tennant, when examining it, drew forth a great many particles of iron with a magnet. Continuing up the river, in a south-westerly direction, fine long and open reaches are passed, on the shingle-flats of which are numerous gold-washings. The same grey sandstone (Specimen No. 22) occurs in situ all along, frequently in reefs, and sometimes scattered on the banks in blocks. At the village of Shih-pow-chai there is a very remarkable geological feature, in the shape of a large isolated mass of rock.† I did not visit it myself, and no specimen of it was obtained. I take it, however, to be of the same sandstone. Before reaching Fu, which will be found on the map at the mouth of the tributary Kung-tan Ho, the course of the river is between mountains ranging N.E. and S.W., which cause a disturbance in the level of the strata; and just above that place, specimen No. 23 of a grey sandstone was broken * A description of the operation will be found in Chap. IX. off a reef where the strata, running W.N.W., dipped about 30° to the N.N.E.; and here we entered a district which, from its peculiar conformation, I have called the "Cross Ranges." By reference to Chapter XII. and the map it will be seen that, from the course the river takes, it is forced to break through these parallel ranges of hills; and at such places we almost invariably found limestone and coal cropping out from under the sandstone, and at some of them iron is worked. Specimens 24, 25, and 26 will speak for themselves of the country near Chung-king, where one of these ranges occurs, running N. by W. and S. by E., out of which coal, lime, and iron are worked.* Above Chung-king the country is still traversed by cross ranges, which can be traced as far even as Sü-chow; and almost invariably, when the river led us through one of them, we saw coal and lime being worked within a few yards of each other. As you get westward, however, their direction changes a little, being sometimes N. and S.† I have already observed that the nature of the river is very much influenced by the way in which it runs with respect to the axes of these hills-the course, when parallel to them, being usually long and straight, and when transverse very variable. A few miles above Chung-king we obtained both hard silicious and soft micaceous and silicious grit, as well as a fine red calcareous sandstone (see Specimens 27, 28, and 29); and thence the general rock was sandstone, sometimes micaceous (Specimens 30 and 31), as far as Na-chi, except where, as before noticed, any of the cross ranges were passed through. Gold-washings were not uncommon on this portion of the river, and there was a good deal of half-solidified conglomerate in different stages of hardness. Moreover, in the tortuous portion of the river in the vicinity of Lu, Ho-kiang, and Kiang-an, *See Chap. XIII. † See Chap. XVIII. there were some deep beds of gravel exposed on the riverbanks, sometimes as much as thirty feet in thickness; and from the general appearance of the river-valley, I came to the conclusion that the bed of the river had in former times been of much greater width, and the water very much higher-the stream now meandering about from side to side of its former bed-just as if some obstruction to its course below had been removed, allowing of its draining off. At Nan-ki there were both limestone and red and grey sandstone (Specimen No. 32) in horizontal strata, or with a very slight dip to the S.E.; and as we approached Sü-chow the N.E. and S.W. ranges became again well marked. Six miles below Sü-chow are the coal-mines of Pa-ko-shan, where specimens of true bituminous coal, carbonaceous shale, and grey shale (No. 33) were obtained; and examination has proved the correctness of our surmises at the time, that at these mines the coal was superior to that found on any other part of the Upper Yang-tsze. Under the influence of heat, the specimens from this place exhibit far more combustibility than any collected lower down; and I have the authority of Professor Morris for stating that the coal of this district is of the above-mentioned description. It was being extensively mined, still by the same horizontal or slightly-inclined galleries elsewhere described, but it was got out in far larger lumps than we had previously seen, and at Sü-chow is used for burning in the pure state. From Sü-chow we brought away a piece of the general rock, which is a purple micaceous sandstone (Specimen No. 34); and we were informed that some iron is obtained in the neighbourhood. Above Sü-chow the country commences to rise rapidly towards a high mountainous region lying to the westward, of which, as far as our wanderings led us-thirty-eight miles farther up-we saw no end. The hills, however, seem to lose any distinct lay, and beyond Ping-shan the view in every direction was nothing but a succession of mountains rising one beyond the other until their outlines were lost in the far distance. Between these two places, Sü-chow and Ping-shan, we passed through a rocky gorge of considerable length, where coal was being worked very extensively, and in a peculiar manner. Specimens of coal, but not so good as at Pa-koshan, and sandstone (No. 35) were preserved. Fall, Discharge, and Course.-On a voyage such as was made by our expedition, the results deduced from barometrical measurements cannot be expected to be anything more than approximations to the truth; but by massing the observations near certain selected stations, I arrive at the following result:-That the Yang-tsze Kiang at Ping-shan, 1550 geographical miles above its mouth, is about 1500 feet above the level of the sea, giving an average fall of 12 inches per geographical mile for its whole course, which may be divided into 10 inches below I-chang, and 14 above that place; and in one part of its upper course as much as 19 inches in the mile. In comparison with other rivers of which I can obtain reliable statistics, this fall is nearly double that of the Nile and Amazon, and almost three times that of the Ganges; while it is but one-third of the Rhone, even below Lyons; little over one-half of that given for the whole length of the Mississippi; and considerably under that of the lower course of the Thames. The force of the current is very variable; but it is seldom sluggish. I find on the Admiralty charts two knots marked as the current for the portion between Hankow and the Tung-ting Lake in March. In June it was about four knots (geographical miles) per hour for thirty miles below I-chang; but below that much less. Between I-chang and Quai-chow * For a description of this, see Chap. XVI. and Dr. Barton's sketch. we found it to average six knots in June, while many of the rapids ran at least ten. At Chung-king in May it was about four. During June, between that place and Sü-chow, it averaged 5.8 knots; above Sü-chow the current carried us down at the rate of six and a half geographical miles per hour; and between Chung-king and Quai-chow it gave an average of 6.4. This river is subject to extraordinary floods; but, as I have noticed these facts in the narrative, I need only here put together the observed differences between the winter and summer levels for 1861. Nanking, 12 feet; Kiu-kiang, 21 feet; Hankow, 33 feet: while, between the 17th of March and the 25th of June, the water at the outlet of the Tungting Lake had risen 20 feet; and at I-chang, between the 1st of April and the middle of June, 15 feet; but I do not believe the Upper Yang-tsze at that time to have been at its highest. The year previous, when there was an unusual flood, it was about 20 feet higher. Much, of course, depends on the width of the river and nature of the banks; and therefore the height at which we observed water-lines in the gorges need not be considered extraordinary, when in a broad part, as at Hankow, this river can rise 33 feet. With regard to the volume of water discharged by the Yang-tsze Kiang, I have no data from which to deduce the total amount; but for the "Upper Yang-tsze," that is, above Tung-ting Lake, I have pretty sure data. From a careful line of soundings across the river, and its breadth by sextant measurement a few miles below I-chang, a section of the river was obtained, the measurements of which give, for the 1st of April, 2700 × 33 89,100 sq. feet; and for June, 2700 x 48 129,600 sq. feet; this, taking an average current of three knots, which I believe is quite below the mark, gives a discharge of 466,000 cubic feet in one second of time in the first case, and 675,800 in the other. Thus, I = = |