THE VICTORIAN NATURALIST. 39 



Since, then, we can safely assign the formation to the human 

 period, there is nothing inherently improbable in such impressions 

 as we have been considering being due to human beings ; and, 

 also, seeing that the tracks of birds and other animals have 

 undoubtedly been preserved, there is no reason why human foot- 

 prints should not also have been preserved in the same way. 



NOTE ON MUSICAL SANDS. 



By T. S. Hall, M.A. 



(Bead before the Field Naturalists' Club of Victoria, 9th 3fay, 



1892.) 

 While on a trip to Phillip Island at Christmas time I was struck 

 by the musical note given out by the sea sand when walked over. 

 I had never noticed this phenomenon before, though it occurs 

 not uncommonly in other parts of the world. My first idea was 

 that the sound was caused by the india-rubber soles of my shoes, 

 but I found I could get the musical note by striking the sand 

 with my hand, or by drawing a stick rapidly over the surface. 

 The sound was produced only where the sand was dry, and 

 resembled almost exactly that caused by drawing the finger 

 rapidly over a piece of corded silk. On making the sound by 

 skating over the surface, I found that the note could be detected 

 at a distance of forty paces. The sands were musical wherever 

 I tried them about Cowes, and the only gentleman to whom 1 

 spoke who had noticed the phenomenon said he had also noticed 

 it at San Remo. I have since tried the sand at Geelong, Barwon 

 Heads and Warrnambool without any result. Probably other 

 members of the club have noticed the phenomenon elsewhere. 



Mr. Cecil Carus Wilson gives some interesting notes on 

 musical sands in Nature of last year (vol. xliv., p. 322), and his 

 experiments go to show that the sound is caused by the rubbing 

 together of millions of grains of perfectly clean quartz, free from 

 angularities and all about the same size. This theory, which was 

 put forward some years previously, has been opposed by Dr. A. 

 A. Julien, and Prof. H. C. Bolton, of the United States, who have 

 given some attention to the subject (Nature, vol. xliii., p. 30). 

 They hold that the grains are prevented from actual contact by 

 an elastic air cushion, consequently the note is given out only 

 when the sand is dry. In two localities in the United States 

 " squeaking sands" occur which give off a different sound when 

 disturbed, and then only in the moist state. They believe that 

 Mr. Carus Wilson's theory would explain the latter phenomenon, 

 but not the former. 



The three observers mentioned agree that localities for musical 

 sands are not rare, but observers are lacking, and they have pub- 

 lished lists of such localities as far as known. Inland sands as 

 well as sea sands may be examined, as one of the most remark- 

 able displays was noticed by Prof. Bolton in the Sinai Desert 



