276 THE JARRAH OF WESTERN AUSTRALIA. [Feb. 



other. The length of time necessary to complete this process must 

 be great. Crystals of quartz an inch in diameter by constantly 

 rolling over each other would have their sharp angular faces more 

 or less worn away in a single year. The power involved is simply 

 the momentum of one crystal falling over another. But the 

 momentum with a given velocity is directly as the mass of matter. 

 How long would it require to thus grind a crystal of sand l-40th 

 of an inch in diameter ? In similar bodies the mass of matter is 

 directly as the cube of the diameter. But (1-40)' equals 1-64000, 

 or crystals of sand 1-40 inch in diameter would require 64,000 

 years to receive the same grinding effect by rolling over each other 

 in the lazy laps of the waves, that a crystal one inch in diameter 

 would receive by the same process in one year. And when we 

 consider how small a fraction of its existence the sand crystal might 

 be supposed to be under the action of the waves — the ages during 

 which it would lie in moveless sand-banks, or sunk in the stillness of 

 the ocean's bed, we see that the grain of sand, rounded and polished, 

 is not the product of tlie present age, but its history reaches back 

 into that mysterious past before the years were born or the centuries 

 had a beginning. In the crystals of sand we grasp the dust of a 

 past and forgotten eternity ! " 



Thus is it with the sand of the sand plains and sand quarries, 

 and thus is it with much of the sand of the sea-.shore and sand 

 dunes with which it is lined — it has been brought down by rivers 

 from these older deposits. 



THE JARRAH OF WESTERN AUSTRALIA. 



THE wonderful capabilities of this eucalypt, E. marginata, was 

 the theme of the majority of speakers in the discussion 

 following Mr. Simmonds' paper. Of the twelve sawmills in the colony, 

 the most important are the Jarrahdale Company of Eockingham, 

 with a railway to the port 23 miles long, employing nearly 200 

 hands ; the Western Australian Jarrah Company, at Lockville, 

 with 16^ miles of tramway; Davie's Karridale sawmills at 

 Angasta and Port Hanelin, with 6 miles of tramway, and 

 employing 100 to 150 men ; and the Canning sawmill, with 

 8^ miles of tramway, employing about 50 men. In 1882, 

 there were shipped, chiefly to the neighbouring colonies and India, 

 18,730 loads valued at £93,650, £5 a load; and in 1883, 

 19,940 loads, valued at £79,760, £4 a load. While there 

 is a palpable diminution in the supply of scented wood 



