OF AETS AND SCIENCES. 283 



XXIV. 



HYDROGRAPHIC SKETCH OF LAKE TITICACA. 



By Alexander Agassiz. 



Presented, March 8, 1876. 



From the position of Lake Titicaca, its exploration promised to 

 give interesting results in Natural History, judging at least from the 

 materials collected in lakes situated at great heights. It was there- 

 fore with considerable disappointment that my companion and myself 

 after a protracted examination of this great sheet of water examined 

 our plunder. We had come prepared with all the necessary apparatus 

 for dredging, for taking observations of temperature and making 

 soundings ; and, with the facilities placed at my command by the 

 Peruvian government, we hoped to gather a rich harvest. Mr. Gar- 

 man spent nearly six weeks in skirting the shores of the lake, stop- 

 ping at all convenient places for making collections of the Fauna of 

 the lake and of its shores, and for exploring the ancient remains found 

 on the islands in the lake and at several points in the vicinity of the 

 shore line. While Mr. Garman was sailing on the lake in a small iron 

 sloop, the only sailing vessel on the lake, if we except an old flat bot- 

 tom ferry plying across the Straits of Tiquina, I made two expedi- 

 tions in the steamers " Yavari " and " Yapura " placed at my disposal 

 by the Peruvian government, landing at all the noted points where 

 interesting Inca ruins existed : the islands in the lower lake, the islands 

 of Coati and of Titicaca, Copacabana, and Tiaguanaco. During these 

 two expeditions, I crossed the lake longitudinally twice, and ran sev- 

 eral lines of soundings from shore to shoi'e. The ca[)tains of the 

 government steamers, Capt. F. Guerrero especially, taking the great- 

 est interest ia my proceedings and assisting me in all possible ways, 

 sparing neither time nor pains to secure proper observations. The first 

 mate of the " Yavari " was fortunately assisted by a number of English 

 sailors, who were devoted in haulina" the soundino; Hues at all times of 

 the day and during all kinds of weather. The sketch map accompany- 

 ing this notice is compiled from the map of Thompson aud of Pentland, 

 with such corrections of the shore line as we could make from per- 



