88 S. Nakamura and K. Honda. 



§ 8. Chüzenji Lake. 



Nikkö, a place noted for its beautiful sceneiy and splendid 

 temples dedicated to the first and third Shoguns, lies within about 

 100 kilometres north of Tokyo, and is a favorite summer resort of 

 foreign residents. Among the mountains not far from Nikkö, 

 is the famous and picturesque Chùzenji lake. It is nearly 

 surrounded by steep and thickly wooded mountains, the great 

 Nantai-san grandly towering on its northern side. The lake 

 is about two kilometres wide and six kilometres long, its surface 

 being 1316 meters above sea level. It is one of the deepest lakes 

 in this country, and its greater part has a depth exeeding 100 

 metres, the maximum depth being 172 metres. The sounding of 

 the lake was carried out by Viscount A. Tanaka, a zealous limno- 

 logist, who has very kindly allowed us to make use of his results 

 and also to reproduce them in Plate XVIII. 



During the summer vacation of 1905, a limnimeter of the 

 ^'H" type was set up at Chüzenji, a village near the eastern end of 

 the lake, and a series of limnograms were obtained continuing for 

 24 hours. The curve is a smooth sine curve, as is shown by the 

 accompaning figure (26) in which a, and h are curves for two 



Aug. 27, 1905. 



4Cm ,3(,»rt it«» IQm ,?C'« 36»» 



Fig. 2'j a. 



Aug. 27, 1905. 



2h 4^ 6'» 6'» lO^^ 



fig. 26 b. 



