Abstract
At the time of the great earthquake on September 1st the level of Lake Tyuzenzi situating toward NNW of Tokyo at the distance of about 120km had depressed about 2 feet at the shore near Tyugusi and recovered after about ten minutes. At the shore near Syôbugahama, the depression was about 0.5 or 6 foot and the time wanted for recovering was 5 minutes. Hence the water of the lake seems to have swung from NE to SW and then drew back. On the same occasion the water of six secondary cascades of Kegon Waterfall hanging at the end of the lake changed its colour and became turbid for about 22 hours, which seems to have been caused by some internal break of rocks at the boundary of the stratum of conglomerate mounting on the bed of quartz porphry. The water of the remaining six of the secondary cascades and the primary waterfall remained unchanged.