294 SIR RODERICK I. MURCHISON'S ADDRESS— ASIA. [May 23, 1859. 



tance of about 1250 miles, was performed in the short space of 46 

 days, exclusive of 12 days spent off the city of Kew-Keang; and, 

 when we peruse the livel}'' and clear description of Mr. Oliphant, 

 our surprise rises to admiration. It is then that we find what 

 difficulties our gallant seamen encountered and overcame, caused by 

 the extraordinary changes which are continually going on in the 

 banks and bottom of the great river. Seeing that in the year 

 1844 the river had been already and accurately surveyed, as far as 

 Nankin, by those excellent officers Kellett and Collinson, it might 

 have been expected that up to that point at least, the charts might 

 to some extent be depended on; but, as Oliphant narrates, "24 

 hours had scarcely elapsed before every ship in the squadron had 

 discovered a new sandbank by feeling it with her bottom. Shoals 

 had been converted into islands, or had disappeared altogether, and 

 the spot formerly avoided as a danger was now discovered to be the 

 deep and safe channel. But this entire transformation was not con- 

 fined to the bed of the river alone. In some places its banks were 

 similarly affected, former landmarks having disappeared or become 

 so altered as to be no longer distinguishable." Farther up the 

 stream, as the voyagers neared Nankin (and where landmarks have 

 not changed), 6 feet of water only were sounded where Collinson 

 had found 6 fathoms. These remarkable variations, common to all 

 rivers having a long course over alluvial tracts, although not to the 

 same extent, show that if a steady commerce is hereafter to be 

 carried on, the re -surveys of the stream must be frequent. 



A few observations on these striking natural phenomena may here 

 be permissible. Descending in two main streams from the Pering 

 mountains, which divide China proper from the unknown regions of 

 Tartary, the Yang-tse-Keang, which is estimated to have a length 

 of 3300 miles, is thus remarkable in being navigable by large 

 ships for upwards of a fifth part of its whole length ! Being the 

 largest river in the Old World of geographers, and exceeded only 

 by the Mississippi and the Amazon in the New World, this long 

 body of water is swelled by numerous affluents, chiefly from the 

 north, but also by some on its southern shore. The former, flowing 

 from lofty snow-covered mountains, and consequently rushing forth 

 with great vehemence in the early summer season, necessarily carry 

 down with them vast quantities of sand and detritus, thus explaining 

 how, in its course seawards, the trunk-stream is either rapidly ob- 

 structed in one part of its bed, or deepened in another by new and 

 powerful currents. Thus it is that in no part of the civilized world 



