PRESIDENT S ADDRESS. Clll. 



i, 200 feet. Combustions of the shale have occasionally taken 

 place on the Dorset Coast, as in the case of the Burning Cliff at 

 Holworth : one of these is now in progress a short distance to 

 the East of Lyme, and a considerable landslip has also occurred 

 in the same locality. A paper on these phenomena will be 

 found in the present volume. Another cause of serious damage 

 to land at the Cape has been erosion by storm water on a large 

 scale, which is being combated. The age of Niagara Falls has 

 been estimated at 39,000 years. The Canada geological survey 

 reports the existence of enormous quantities of coal in the Yukon 

 region, so that when the supply of our own country is exhausted 

 we shall no doubt have to look to our colony. The supply of 

 petrol, the demand for which has more than doubled in three 

 years, will have to be considered, or some other similar fuel 

 adopted in the near future in its place. Luminosity has not infre- 

 quently been observed on hills during great earthquakes, and also 

 at other times on the face of quarries of chalk or clay slate. It 

 would appear from experiments that these may be of an electric 

 nature. A most interesting account of earthquakes was given by 

 Professor Milne on March 2oth, at the Royal Institution, in which 

 he describes experiments showing that certain valleys become 

 wider by day and close up somewhat at night. He considers that 

 these extraordinary movements are caused by the greater amount 

 of water which reaches the bottom of the valley at night owing 

 to the decreased evaporation. This, by its weight, depresses the 

 bottom of the valley. Amongst other curious effects of earth- 

 quakes he gives an amusing quotation from a New England paper 

 of 1727, which states that "a considerable town in this province 

 has been so far awakened by the awful providence in the earth- 

 quake that the women have generally laid aside their hooped 

 petticoats." Ot the 674 tons of gold produced in 1906, one 

 third is stated to have come from South Atrica, one-fifth from 

 Australasia, and a quarter from the United States and Alaska. 

 In the latter country it has been found that the gold deposits are 

 produced from long- continued concentration from rocks which 

 contained only very minute quantities, and not from the wearing 



