22 S. Xakamiira and K. Honda : 



§ 2. Lake Biwa. 



Lalce Biwa, the largest lake in our country, is situated in the 

 central part of the main island of Japan, where the land is 

 considerably narrowed by the encroachment of the bay of Suruga 

 on the northwest and of the bay of Ise on the south. It is 

 more than GO kilometers in length and 16 kilometers broad in 

 its widest part (PL VI). Its surface is 8G meters above sea 

 level. The lake has a narrow constriction near Katada (Point No. 

 11 on the map) which joins the great north basin with shallow 

 southern one of almost negligible size. The Jake in fact takes 

 its name from the shape of the hiira, a musical instruu:ient 

 somewhat like a guitar, the south basin lepresenting the neck 

 of the biwa. The. north basin has two very deep places in it. 

 The deeper one lies ofï Imazu and has a depth of more than DO 

 meters, so that the bottom of the lake at this place is l^elow sea 

 level; while the other, about 70 meters deep, lies between Ka- 

 tsuno and Wani. The lake is surrounded on almost all sides 

 by mountains, conspicuous among which are Hiei-zan on the 

 west, and Ibnkiyama on the east. The large river Seta flows 

 from its southern extremity, and passing through the cities of 

 Kyoto and Osaka, empties into the bay of Osaka. 



Owing to the lack of necessary equipment, a bathymétrie 

 survey of the lake was not carried out at that time, but happily for 

 us Mr. Maeda of the Hikone meteorological station made it 

 afterwards and published a map, which has been of great service 

 to us. It is reproduced in Plate VI. 



Our observations consisted of two series; the first series was 

 begun on the '>0 th. of July 1901 and continued to the 23rd of 

 August, this was the first systematic study of seiches ever under- 



