Seiches in Some Lakes of Japan. 



Fig. 2). This new instrument was used at lakes Tuya and Chü- 

 zenji. It consisted of a buoy fjind a thin wire or string which 

 was attached to the buoy and after passing over a pulley was 

 stretched vertically by means of a counterweight. The buoy was 

 made of slieet zinc and was cylindrical in form, having a diameter 

 of 12 cm. and a height of 10 cm. In order to give the buoy some 

 steadiness, it carried a lead weight on its lower end, or was 

 partially filled with water through a hole made for the purpose and 

 closed by a screw. The pulley had a diameter of 3 cm. and its 

 horizontal axis rested in two agate cups. The counterweight was 

 of lead, and Aveighed about 300 grams. By means of a pen 

 attached to the wire, the up and down motion of the Avire was 

 recorded on a Richard's vertical cylinder which made a complete 



rotation either once a day or once 

 every two hours. To give steadi- 

 ness to the pen, and at the same 

 time to diminish the friction as 

 much as possible, the penholder 



"fv- ± L -w Vn had two horizontal arms, at each 



end of which a friction wheel 

 was fixed and made to run in V- 

 shaped grooves cut in tAvo vertical 

 guides; and in order to make it 

 easy to adjust the height of the 

 pen, the, penholder was attached 

 to the wire in following wa}^ At 

 the point where the penholder 

 Avas to be attached, the string was 

 divided into tAA^o strands, and these 

 Fig. 2. tAvo strands Avere passed through 



Id 





