Account of Travels letween the Tropics. 55 



lidong to a new genus of ihn pentandria monogi/ma, with 

 alternate leaves. 



Frouj Loxa they entered Peru hy Ayavaca and Gounca- 

 bamba, traversing the high summit of the Andes, to pro- 

 ceed to the river Amazon, They had to pass thirty-five 

 times in the course of two days the river Chamaya, some- 

 times on a raft, and sometimes by fording. They saw the 

 superb remains of the causeway of Ynga, which may be 

 compared to the most beautiful causewavs in France and 

 Spain, and which proceeds on the porphyritic ridge of the 

 Andes, from Cusco to Assonay, and is furnislied with 

 tamlo (inns) and public fountains. Thev then emliarkcd 

 on a raft of othroma, at the small Indian village of Cha- 

 uiaya, and descended by the river of the same name, to that 

 of the Amazons, determining by tlie culmination of several 

 stars, and by the difference of time, the astronomical posi- 

 tion of that confluence. 



La Condamine, when he returned from Quito to Para and 

 to France, embarked on the river Amazon only below 

 Ouebrada dc Chucunga; he therefore observed the longi- 

 tude only at tlic mouth of the Rio Napo. M. Humboldt 

 endeavoured to supply this deficiency in the beautiful chart 

 ot the French astronomer, navigating the river Amazon as 

 far as the cataracts of Rentema, and forming at Tomependa, 

 the capital of the province of Jaen de Bracamorros, a de- 

 tailed plan of that unknown part of the Upper Maranon, 

 both from his own observations and tlie information ob- 

 tained from Indian travellers. M. Bonpland in the mean 

 time made an interesting excursion to the forests around 

 the town of Jaen, where he discovered new species of cin- 

 chona ; and after greatly suffering from the scorching heat 

 of these solitary districts, and admiring a vegetation rich in 

 new species of Jacquinia, Godoya, Porferki,^Baugai/ii'illeaf 

 Odieiia, and Pisonia, our three travellers crossed for the 

 fifth time the cordillera of the Andes by Monlan, in order 

 to return to Peru. 



They fixed the point where Borda's compass indicated the 

 zero of the magnetic inclination, though at 7 degrees of 

 soulh latitude. They examined ihe mines of Ilualguayoc, 

 wliere native silver is found in large masses at the height of 

 2000 toises above the level of the sea, in mines, some 

 metalliferous veins of which contain petrified shells, and 

 Avhich, with those of Huantajayo, are at present the richest 

 of Peru. From Caxamarca, celebrated by its thermal 

 watcr.s, and by the ruins of the palace of Atahualpa, they 

 deicended to Truxillo, in the neighbourhood of which arc 

 D 4 found 



