SEICHES AND OTHER OSCILLATIONS 
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essentially of a large and very sensitive barograph (Richard 
statoscope), DSS, which is connected with a closed well, W, placed 
partly in, partly out of, the lake. The rise and fall of the lake-level 
causes a corresponding rise and fall of the water-level inside this 
closed well, thereby increasing and diminishing the air-pressure in the 
Fk;. 10. 
cylinder, SS, into which are fixed the barograph capsules, which are 
thus compressed and extended like the bellows of a concertina. This 
compression and extension are transferred by a system of multiplying 
levers, working the pen which writes on the recording drum, D. 
The inertia of the working parts is very small, and the sensitiveness 
to alteration of pressure is fifteen or twenty times that of an ordinary 
mercury barometer. The instrument will therefore show quite plainly 
extremely small denivellations of the lake, and it can be made more 
