342 TJIACKING — MEASUREMENT. April 



strength of the stream ; so landing all our party, except two 

 in each boat, we made the boats fast to one another, at a few 

 yards apart, in a line a-head : and then taking the end of a 

 coil of whale-line ashore, half our party fixed themselves to 

 it by laniards of broad canvas straps, which passed across 

 their breasts and over one shoulder, and walked together 

 steadily along the river's bank. The bight of the line was 

 passed round a stout mast, stepped in the headmost boat and 

 attended by the two men, who veered away or shortened in 

 the line as the varying width of the stream, or frequent impe- 

 diments rendered necessary. In this manner, one-half of our 

 party relieving the other about once an hour, every one wil- 

 lingly taking his turn at the track rope,* we made steady 

 progress against the stream of the river, which rather increased 

 in rapidity as we ascended, until its usual velocity was be- 

 tween six and seven knots an hour. While among the islands 

 which I mentioned tracking was difficult and tedious, many 

 were the thorny bushes through which one half of the party 

 on the rope dragged their companions. Once in motion no 

 mercy was shewn : if the leading man could pass, all the rest 

 were bound to follow. Many were the duckings, and not 

 trifling the wear and tear of clothes, shoes, and skin. At 

 intervals stoppages were made for refreshment and obser- 

 vations. 



Three chronometers were carried in the boats, with other 

 necessary instruments : among them two mountain barome- 

 ters, with which Mr. Darwin and myself wished to measure 

 the height of the river above the level of the sea, and the 

 heights of the neighbouring ranges of hills above the level of 

 the river. This afternoon we picked up a boat-hook upon the 

 south bank of the river, which was immediately recognized 

 to be one which had been left by accident sticking in a mud- 

 bank, by the party who accompanied Captain Stokes in his 

 excursion up this river in the year 1827. 



It was very cold at our bivouac this night, being a sharp 



* Mr. Stokes alone being- excepted, as his duty required continual 

 attention. 



