It will be noticed that very liberal allowances have been made for delays at the head and foot of the incline, and for the friction of the gravity system. The friction of train, sheaves, etc., has been allowed for in determining the inclination. And the extra five tons weight of counterweight over that of the maximum train is not only sufficient to overcome any resistance due to curvature, but would render some assistance to the locomotive. In conclusion, it may be added that in the construction of such a system due reference should be paid to the arrangement of the grades so that the maximum train, on that portion of the line which is arranged as a supporting grade, should be able to pass over the planes. Or the arrangement might be made with reference to the division of the trains at the foot of the planes, in which case it would be necessary to make two or more trips over the planes for each train. THE RIVERS OF CHINA. THE YANG-TSE, THE YELLOW RIVER, AND THE PEI-HO. THESE three rivers form conjointly the great river system of China. Although at the present day each of them runs its separate course to the sea, there is good reason to believe that several centuries since they were united by a number of connecting branches, in a manner somewhat resembling the junction of the Ganges and the Brahmapootra in our own time. Such is the inference to be drawn from an ancient Chinese map, copied by Alvarez Semedo, a Portuguese Jesuit, and which must be assigned to a time preceding that of the construction of the Grand Canal by Ghenghis Khan in the beginning of the thirteenth century. Linked together as these riv The author, Surgeon H. B. Guppy, of H.M.S. "Hornet," writing from Yokohama, February 11, says: "I forward to you by this mail a paper containing the results of observations I have made during the last two years on the subject of the Yang-tse and the Pei-ho, together with similar information as regards the Yellow River. Looking on these three rivers as in reality one river system, I have embodied in one paper all the "data" concerning them; and have treated them both separately and in their conjoint character. I can answer for the accuracy of the various estimatione, and have employed the usual methods in obtaining them.' + Vide a paper by Mr. S. Mossman on the "Double Delta of the Yellow River," published in the Geographical Magazine for April, 1878. * ers were in the past, a brief consideration of their present condition will prove that they are laboring towards the same end in our own day. But before proceeding to examine them in their conjoint character, it will be necessary to consider briefly their leading hydrological features. I. The Yang-tse-the largest and most important of these three rivers-has a course of about 3,000 miles, and drains an area which is variously estimated between 750,000 and 550,000 square miles; for my own calculations I will adopt the mean of these two estimates, namely, 630,000 square miles. Its waters, commencing to rise in February and March, reach their highest level in the month of June or July; and here they remain with occasional fluctuations till the end of August or the beginning of September, finally reaching their lowest level towards the close of January. With regard to the discharge of water of this river, Capt. Blakiston has esti "Five months on the Yang-tse." 2188 mated the average amount carried past the river was at its height; while in T-chang, which is situated at about 960 March, when the river was low, I found miles from the sea, at 500,000 cubic feet as little as three-fifths of a grain per per second; he founded this estimate on pint. The average proportion of sediobservations made during the months of ment during the twelve months in quesApril and June. When stationed at tion I estimate at four grains in the pint Hankow in the winter 1877-78, a place (a little over half a drachm per gallon). distant about 600 miles from the sea, I This represents a proportion of ss by set to work to make a similar estimate of "weight," or (taking the specific gravity the water carried past that city for the of the dried mud at 1.9) of by twelve months included between May "bulk" of the average discharge of 1877 and May 1878. Having taken a water. It is thus easy to obtain the line of soundings across the river and total amount of sediment carried during having ascertained the river's breadth the twelve months past Hankow, namely, (1,450 yards by sextant measurement) at 4,945,280,250 cubic feet but to allow a point below the union of the Han with for the amount of mud a river pushes the main stream, I commenced a series along its bed, one-tenth must be added of observations on the rise and fall of according to the principle laid down by the river water and on the force of the Messrs. Humphreys and Abbot in the current, which combined with informa- case of the Mississippi. This will bring tion received from the Custom-house and the total annual discharge of sediment from other sources, supplied me with at Hankow up to 5,439,808,275 cubic the necessary data for my calculation. feet, or at the rate of 172 cubic feet per The results are contained in the follow- second. Now, assuming that the draining table: age area below Hankow supplies the same Water-discharge. relative amount of sediment as the remainder of the catchment basin, I estimate the total amount carried down to the sea annually at 6,428,858,255 cubic feet. 1877. Surface current. May 31.. Knots per hour. *Average 64 June 30.. 21/ 61 July 31.. 3 58 Aug. 31.. Sept. 30.. Cubic feet 622,997 141,085 12)7,822,502 651,875 The removal of this amount of sediment from an area of drainage of 650,000 square miles represents a lowering of the surface at the rate of one foot (of rock) in 3,707 years. This is therefore the rate of "subaërial denudation" of the valley of the Yang-tse as far as concerns the quantity of sediment removed. Of the proportion of solids in solution, I have had no opportunity of judging, but that the soluble matter is in considerable quantity is rendered probable from the extensive limestone districts traversed by II.-The Yellow River or the Hoang-ho We may therefore place the average water-discharge for the year at Hankow at 650,000 cubic feet per second. Now, this river. estimating the area of drainage above Hankow to be about of the whole has derived the appellation of “China's area, and assuming that the portion of the Yang-tse valley below Hankow drains off its waters at the same rate as the remainder of the river-basin, it follows that the average water discharge for the whole river may be placed at 770,000 cubic feet per second. With reference to the amount of sediment carried by the Yang-tse past the same city, I found, as much as seven grains in the pint (nearly one drachm in the gallon) in the month of July, when Sorrow" from its frequent destructive inundations. It runs a course of about 2,500 miles; but, unlike the Yang-tse, its lower course has frequently shifted in the course of ages, and although it opens at the present day into the Gulf of Pechili, only a quarter of a century has passed since it emptied its waters into the Yellow sea.* The mountainous district of the province or Shantung has in truth been the chief means in deflecting * Vide Mr. Mossman's paper, already referred to. the waters of this great river on more than one occasion during the historical era from the Gulf of Pe-chili to the Yellow Sea and vice-versa. I found in the water of the Yang-tse was seven grains in the pint, and in the case of the Pei-ho-as will subsequently be noticed-fifteen grains in the pint, Sir With reference to the quantity of George Staunton estimates the sediment water discharged by the Hoang-ho I of the Yellow River at over eighty have had no opportunity of personal grains in the same measure of water. observation. We have, however, an es. Even the muddy waters of the Ganges timate not only of the water discharge, do not contain more than twenty grains but also of the sediment, which Sir of sediment in the pint of water. George Staunton supplies us in his account of Lord Macartney's embassy to China in 1792. It was calculated that at the place where the British embassy crossed the Yellow River-its junction with the Grand Canal-the water was carried past at the rate of 418,176,000 cubic feet per hour, or 116,000 cubic feet per second. The method employed in ascertaining the quantity of sediment was the measurement of the amount of mud deposited from a gallon and threequarters of water when allowed to stand. From this experiment it was concluded that the sediment was in the proportion of of the original bulk of the water, and the annual discharge of sediment was assessed at 17,520,000,000 cubic feet. It is therefore not with any surprise that I find the "subaërial denudation of the Hoang-ho is estimated * at less than half that of the Yang-tse, namely, one foot in 1,464 years. This estimate only refers to the amount of sediment removed, and yet I cannot but consider it as very liable to correction by some future observer. As this is the only calculation that has ever been made, as far as I am aware, with reference to the quantities of sediment aad of water discharged by the Yellow River, I am perforce obliged to accept it as pro tanto. III.-The Pei-ho drains the great plain which constitutes the province of Pechili. Its length is said to be about 300 miles, but the lower part of its course below the city of Tientsin is so tortuous that a distance of thirty miles overland is converted into fifty by the river. It is at Tientsin that the Pei-ho proper and the Yu-ho unite together to form the main stream; the latter is generally known by matter of fact the canal joins the Yuho about 150 miles to the southward. During the three winter months-December, January, and February—the Peiho is usually frozen over, the ice having a thickness of about eighteen inches; in the same season there is generally a large quantity of ice in the Gulf of Pe-chili, which may completely fill up the head of the gulf. However carefully these observations may have been made, and however near they may approach the actual discharge of water and of sediment at the time in question, it seems to me that one is hardly justified in accepting the result of a single observation as typical of the average Europeans as the Grand Canal, but as a state of things throughout the year; and yet Sir George Staunton's estimate has never, as far as I am aware of, been questioned. A single glance at the foregoing table will convince one of the little dependence that can be placed on a solitary estimation; it will be there seen that the Yang-tse discharged nine times as much water when at its highest level in August as it did during the month of January, when its waters occupied their With reference to the water discharge lowest level.* Or if the question of sedi- of this river, Iwas enabled while winterment is considered, to which the same ing at Tientsin during the season 1878objection would apply, I have the great- 79, to collect some "data" for its estimaest diffidence in accepting Sir George Staunton's estimate as being of any value, except as a trustworthy result o a single experiment; and yet, even considered as the maximum of the whole year, the result is rather a startling one. While the greatest amount of sediment In the case of the Ganges at Ghazepoor the proportion is as 1 to 14. VOL. XXIV.-No. 1-5. tion during the four months from December to March. Although my estimate strictly applies to but a third of the year, still from the limited rise and fall of the water during the different seasons (it never exceeds six feet) I feel pretty confident that it fairly represents the average rate of discharge during the whole * Vide Nature, vol. 18, p. 288. tions: year. The breadth of the river at the January and February it did not equal a place of observation below the city of grain in the pint.) This represents a Tientsin was 280 feet. The following proportion of by "weight," or table contains the results of my calcula- by "bulk" of the average discharge of water; and following the same method. of calculation as was employed in the case of the Yang-tse, I estimate the annual discharge of sediment for this river at 80,000,000 cubic feet. 1878. Surface current. Knots per hour. December 1879. January.. 1 12 Water discharge. Average 14 .. 141 16 14 4,389 9,684 10,592 Now the removal of this bulk of material from an area of drainage, which I estimate at 55,000 square miles, represeuts the lowering of the surface of one foot in 25,218 years. This is the rate of "subaerial denudation" of the Pei-ho basin, omitting of course the question of the solids in solution. Now with regard to the amount of To show the rank that these three sediment carried past the city of Tient- rivers hold in the fluvial system of the sin I found the average quantity globe, I have subjoined a list of fourteen during the four months in question other rivers which gives the quantities to be about five grains per pint. (It of water and sediment discharged by varied much at different times, for I each, as well as the rate of subaerial defound as much as fifteen grains in the nudation, as far as I have been able to middle of March, while in the months of ascertain. We have now the necessary "data" for considering these three rivers in their conjoint character. Together they drain an area of 1,105,000 square miles; they discharge a body of water equal to 894,000 cubic feet every second; and they carry down every year to the sea 24,028,800,000* cubic feet of sediment, which represents a rate of subaerial denudation equal to the removal of one foot of solid rock in 1,687 years. low Sea during the preceding ages. In either event the union of these three rivers would follow. Such being the case, it may be interesting to speculate on the time required by these rivers to fill up the seas into which they discharge their sediment. Sir George Staunton estimated that at the rate the Hoang-ho was discharging sediment it would fill up the Yellow Sea and the gulfs of Pe-chili and Lian Tung in 24,000 years; but M. Elisée Reclus is of opinion that this estimate ought to be doubled, as the Yellow Sea is much deeper than Sir George Staunton stated it to be (20 fathoms). On carefully examining the latest charts of these seas I am inclined to consider that this estimate cannot be assailed on this point, as my own determination of the average depth is 22 fathoms. If we look upon the Yang-tse, the Yellow River, and the Pei-ho as laboring, with the assistance of the gradual elevation of the sea border, which is at present going on, to extend the territory of China seaward towards her ancient coast-line-represented by a line running from Kamtschatka through the Kurile Islands, Japan, the Loo-choo group, Formosa, down to the Malay Archipelago; † and carry ourselves forward into the We will now attempt to gauge the future when such task is completed and the time that the three rivers in question the waves of the Pacific beat once more would require to fill up, by the sediment against this old sea border, we shall not they deposit the portion of the sea which have much difficulty in picturing to our- is included by the gulfs of Pe-chili and selves what will then be the state of Lian Tung, the Yellow Sea, and the matters. In the place of the gulf of Eastern Sea north of the 29th parallel Pe-chili and the Yellow Sea there will and west of the 126th meridian. I have be vast alluvial plains traversed by the placed the total surface area at 200,000 waters of the Yang-tse, the Yellow English square miles, and the average River, and the Pei-ho; but before depth at 26 fathoms; and following Sir the ancient coast line is reached they George Staunton's mode of estimation I will have joined to form one great river find that it would take sixty-six days and one united delta. If the Yellow to form an island a mile square reaching River confines itself mostly in future up to the surface of the sea. At this ages to its course into the gulf of Pe-chili, rate it would require 36,000 years to form that gulf will be filled up in process of all the sea in question into dry land, suptime; and the Hoang-ho winding along posing of course that there was no elethrough the bed of this obliterated sea vation or depression of the sea-bottom will, after being joined by the Pei-ho, during that period. But the recent forturn its course south ward, deflected by mation of several islands and shoals in the Corean peninsula, until it meets at the Yang-tse estuary, the occurrence of length its sister stream. On the other raised beaches and marine remains at hand, should the Yellow River be mostly Hang-chau, Wusung, and Chefoo, with occupied in future in advancing its other similar evidences, demonstrate southern delta it will join the Yang-tse at a period much less remote from the present; and their united waters will pursue an easterly direction subsequently to be joined by the Pei-ho, which will have been gradually finding its way through the gulf of Pe-chili and the Yel In "Page's Advanced Text-book of Geology," Staunton's estimate of the sediment discharged by the Yellow River has been erroneously applied to all "the great Chinese rivers." that there is an elevation of the coast going on at present; and, in that case, it will require considerably less than 36,000 years to form the sea into terra firma. Perhaps Sir George Staunton's original estimate for the Yellow River may not be far wrong when applied to the whole sea in question. IN Western Australia the construction † Vide a paper on this subject, by Mr. A. S. Bickmore, of a telegraph line to Roeburne is under read before the North China branch of the Asiatic Society in November, 1867. consideration. |