4S6 



NA TURE 



[Sept. 23, 18S0 



is that women already are, as a rule, somewhat inferior in 

 mental power to men, forgetting that they were precisely I 

 made inferior by the obstacles thrown for centuries in the 

 way of their advance (some of these specially fixed by 

 legal enactment), and which are sometimes of such a 

 kind as almost to amount to a tax on liberty. It may 

 well be conceivable that the law of inheritance, though it 

 has achieved a vast amount, may not have been able to 

 combat these artificial conditions for producing inferiority 

 with entire success. The above plea of existing inferiority 

 in mental power, therefore, so far from being an argument 

 against female education, ought, when justly viewed, to 

 be regarded as the strongest reason the other way. For 

 if obstruction has produced — in spite oi^ the powerful coun- 

 tervailing influence of the law of inheritance — a certain 

 degree of inferiority : so (conversely) by equally reliable 

 casual sequence encouragement would produce an effect 

 in the opposite direction. IMoreover, precisely on account 

 of the fact that woman is already somewhat handicapped 

 by nature in the race of progress, would there be all the 

 more reason why every encouragement should be given ; 

 i! for/iori, all artificial hindrances in the way of advance- 

 ment removed. It would be a great mistake if the idea 

 w^ere for one moment entertained that progress can be 

 accomplished by letting matters generally drift under the 

 influence of prevailing custom. If there is one thing more 

 certain than another it is that man can never hope to pro- 

 gress with satisfactory rapidity without having a sharp 

 eye to the conditions necessary for this object, and 

 examining (by the light of reason and knowledge gradually 

 acquired) all his customs, to see if they are desirable or 

 •not. To facilitate this end the history of past progress, 

 unfolded in the theory of evolution, may afford some 

 valuable instruction. The increasing appreciation of the 

 value of co-operating with the weak, instead of domi- 

 neering over them, may be perhaps regarded as one of 

 the most pleasing accompaniments to the advance of 

 science. S. Tolver Preston 



THE YANG-TSE, THE YELLOW RIVER, AND 

 THE PEI-HO ■ 



'T'HESE 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 

 tinited 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 rivers were in the 

 past, a brief consideration of their present condition will 

 prove that they are labouring towards the same end in 

 our own day. Rut before proceeding to examine them in 

 their conjoint character, it will be necessary to consider 

 briefly their leading hydrological features. 



I. The Yang-tsL~\.\\Q 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 calcula- 

 tions I will adopt the mean of these two estimates, namely, 



'The author, Surgeon H. E. Guppy, of H.M.S. Hornet, writing from 

 \okohama, February ii. says:—" I forw.ird to you by this mail a paper 

 containing the results of observations I have made during the last two years 

 on the 'iubject of the Yang-tse and the P^i-ho. together with similar informa- 

 ti m 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 estimations, and have employed 

 the usual methods in obtaining them." 



- ;■/,/(• a paper by Mr. S. Mossman on the " Double Delta of the Yellow 

 ■Klver, published in the Givgt-aphhal Magazmc for April, 1878. 



650,000 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 occa- 

 sional 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 estimated the average amount 

 carried past T-chang, which is situated at about 960 miles 

 from the sea, at 500,000 cubic feet per second ; he founded 

 this estimate on observations made during the months of 

 April and June. When stationed at Hankow in the 

 winter 1877-7S, a place distant about 600 miles from the 

 sea, I set to work to make a similar estimate of the water 

 carried past that city for the twelve months included 

 between May 1877 and May 1S78. Having taken a line 

 of soundings across the river and having ascertained the 

 river's breadth (1,450 yards, by sextant measurement) at 

 a point below the union of the Han with the main stream, 

 I commenced a series of observations on the rise and fall 

 of the river water and on the force of the current, which, 

 combined with information received from the Custom- 

 house and from other sources, supplied me with the 

 necessary data for my calculation. The results are con- 

 tained in the following table : — 



May 31 



Tune 30 



July 31 



AuguU 31 



September 30 



October 3 \ 



November 30 



December 31 



.S73. 



January 31 



February 28 



Marcli 31 



April 30 



Water-dischnrge. 

 Cubic feet 

 per second. 



. 846,336 



. 896,293 



.. 1,022,656 



.. 1,275.381 



.. 1,018,248 



,. 622,997 

 308,560 



.. 211,584 



141,085 



.. 412,626 



396,720 



670,016 



12)7,822,502 



651,87s 



We may therefore place the average water-discharge for 

 the }'ear at Hankow at 6jO,ooo cubic feet per second. 

 Now, estimating the area of drainage above Hankow to 

 be about W of the whole 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 jjofioo 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 the river was at its 

 height ; while in March, when the river was low, I found 

 as little as three-fifths of a grain per pint. The average 

 proportion of sediment during the twelve months in ques- 

 tion I estimate M four grains in the pint {a. little over half 

 a drachm per gallon). This represents a proportion of 

 vtVs by "weight," or (taking the specific gravity of the 

 dried mud at rg) of jjVr by "bulk" of the average dis- 

 charge of water. It is thus easy to obtain the total 

 amount of sediment carried during the twelve months 

 past Hankow, namely, 4,945,280,250 cubic feet : but to 

 allow for the amount of mud a river pushes along its bed, 

 one-tenth must be added according to the principle laid 

 down by Messrs. HuninV-,- >ys and Abbot in the case of 

 the Mississippi. Tl.!s n ill bring the total annual dis- 

 charge of sediment at Hankow up to ^,4jg,SoS,2~j cubic 

 feet, or at the rate of 172 cubic feet per second. Now, 

 assuming that the drainage area below Hankow sup- 



* " Five Months on the Yang-tse." 



