Seiches in Some Likes of Japan. 



3 



like Hamana it was too insignificant to enable us to determine 

 accurately the length of the pepods of oscillation. Besides the 

 cases of the lakes above mentioned, observations were attempted 

 in Kasumigaura, a body of water covering an area of about 18 

 square kilometers; but no regular oscillation was found, probably 

 owing to excessive shallowness. 



1. Instriisiient. 



Before beginning our work in 1901, we secured a Sarasin's 

 portable limnimeter. A full description of this intrument is given 

 by Ebert in the "Zeitschrift für Instrumentenkunde" 1901, pp. 



193-201, and accordingly is omit- 

 ted here. Thinking it desirable, 

 that observations should be made 

 simultaneously in at least two 

 different places, we constructed 

 for the purpose a limnimeter of a 

 simpler design. (Plate I, Fig. 1). 

 In the accompanying figure 1, A 

 is a hollow triangular brass rod 

 one meter long, which while 

 being allowed to move freely is 

 kept upright by two sets of three 

 rollers R and R', fixed at the two 

 ends of a cylindrical guide tube 

 D. B is a circular brass rod 106 

 •cm. long and one cm. in, diameter. To its lower end a float F 

 made of sheet zinc is clamped by T and its upper end is inserted 

 in the hollow of the rod A, to which it is clamped at a suitable 

 length by T. iVttached to A is a pen P, which is directed 



PIG 1. 



