1908] on Recent Earthq_uakes. 145 



ments was to determine whether valleys always retained the same form. 

 Did they open and shut ? To answer the question I set up on the 

 two sides of a valley horizontal pendulums identical with those which 

 are used to record teleseismic motion. These instruments which are 

 by photographic means self recording, are exceedingly sensitive to 

 small changes in level. What I found was that on fine days the 

 booms of these instruments moved in opposite directions, each away 

 from the bed of the valley. At night the motions were reversed, and 

 the booms moved towards each other, that is towards the bottom of 

 the valley. Several instruments were employed and the records were 

 confirmed by the movements of the bubbles of sensitive levels. Dur- 

 ing the day the records indicated that the sides of the valley opened and 

 at night they closed. The two valleys I worked upon behaved like 

 ordinary flowers, they opened when the sun was shining and closed at 

 night. The best explanation I can offer is that the phenomenon is 

 largely dependent upon the transpiration of plants. This is marked 

 during the day, but not at night. On a bright day a sunflower or a 

 cabbage may discharge 2 lb. of aqueous vapour. A square yard 

 of grass wiirgive off io or 12 lb. The result of this is that during 

 the day underground drainage has not received its full supply of 

 water to load the bottom of the valley. At night time when plants' 

 transpiration is reduced, subsurface drainage is increased, and the load 

 at the bottom of the valley is also increased. Therefore, at night the 

 bottom of a valley, in consequence of its increased water load, is de- 

 pressed, and this is accompanied by a closing of its sides. During the 

 day the load runs off, and the valley opens. This may also explain 

 why soak wells in valleys and streams carry less water during the day 

 than they do at night, and at the same time it suggests that the side 

 of a valley is a bad place for an observatory. Every day as the world 

 turns before the sun, lamp-posts and tall structures salute the same, 

 whilst many valleys open. At night time these movements are 

 reversed. 



One phenomenon which accompanies all large earthquakes, which, 

 however, has never yet received the attention it deserves, is the influ- 

 ence which great disasters have exercised upon the emotions. Imme- 

 diately after the Kingston earthquake, we read of the dazed and 

 almost insane condition of the people. Many were affected with an 

 outburst of rehgious ecstasy, thinking the last day had come. The 

 negro population camped on the racecourse, and spent their time in 

 singing hymns. Somewhat similar scenes took place in Chili : men 

 and women ran hither and thither, mad with terror and devoid of 

 reason. Amid shrieks and sobs, and the wailing of a multitude an 

 Ora pro Nobis or a Pater Noster might now and then be heard. In 

 early civilisations underground thunderings have so far excited the 

 imagination that subterranean monsters or personages have been con- 

 jured into existence, and these in many instances have played a part 

 in primitive rehgions. At the time of an earthquake in Japan, the 



Vol. XIX. (No. 102) l 



