NOVEMBEE 28, 1919] 



SCIENCE 



493 



that many of us are intellectually sick be- 

 cause we have not properly assimilated funda- 

 mental truths and the function of the teacher 

 is to cure such intellectual disease after a 

 proper diagnosis as well as to provide whole- 

 some food for the healthy mind. My advice 

 to the Missouri teachers therefore is : Pro- 

 vide yourself with a considerable variety of 

 pills sugar-coated with scientific history and 

 use them somewhat sparingly like other medi- 

 cine, but be prepared to use them both as a 

 preventative and as a cure whenever the oc- 

 casion presents itself. 



G. A. Miller 

 TJniveesitt of Illinois 



THE SINGING SANDS OF LAKE 

 MICHIGAN 

 The dune region of Lake Michigan extends 

 along its eastern shore from Gary at the 

 southern extremity to Mackinac at the north- 

 ern with comparatively few breaks or inter- 

 ruptions. Throughout this region the sands 

 near the water's edge, in dry weather, emit a 

 peculiar but definite and unmistakable sound 

 when the foot of the pedestrain pushes 

 through them in an abrasive way. This un- 

 usual sound from an unusual origin is a 

 source of great delight to children and an in- 

 citer of the curiosity of their elders, who, 

 however, rarely pursue the subject far enough 

 to arrive at an explanation for it. The sound 

 is produced not only by the leather-shod foot, 

 but is emitted also if the bare foot or hand 

 is struck through the gi'ains or if a stick is 

 trailed, boy-fashion, behind.^ 



1 (See Tlioreau's "Journal," entry of Septem- 

 ber 22, 1858, in "Autumn.") "One mile south- 

 east of the village of Manchester struck the beach 

 of 'musical sand,' .... We found the same kind 

 of sand on a similar but shorter beach on the east 

 side of Eagle Head. We first perceived the sound 

 when we scratched with an umbrella or the finger 

 swiftly and forcibly through the sand; also still 

 louder when we struck forcibly with our heels, 

 'scuffling' along. The wet or damp sand yielded 

 no peeiiliar soimd, nor did that which lay loose and 

 deep next the bank, but only the more compact and 

 dry. The sound was not at all musical, nor was it 

 loud. . . . E , ivlio had not heard it, was 



The sound has been compared or the at- 

 tempt has been made to relate it to that pro- 

 duced by the pedestrian walking through soft 

 snow; to the crunching noise so frequently 

 noticed when walking through snow after very 

 cold weather or by the wheel of a vehicle on 

 such snow; also to the sound emitted by hard, 

 granular snow when one walks through it; 

 but it is like none of these and has a dis- 

 tinctive character all its own. 



In a preliminary way several observations 

 should be recorded as to the bearing of loca- 

 tion and conditions of various sorts on the 

 singing sands. The soimd is produced only 

 when the sand is dry, and apparently the 

 dryer the sand is, the louder the sound pro- 

 duced. In wet weather or when the sand is 

 moderately moist, the sound is not produced. 

 In summer and indeed in the hottest weather 

 the sound seems to be loudest, other condi- 

 tions being the same, but it can be clearly 

 heard at all seasons of the year, including 

 winter, whenever the sand is dry. As one 

 walks away from the water's edge he may be 

 astonished to find out that the sound-pro- 

 ducing sand ceases rather abruptly about fifty 

 to one hundred feet from the shore line. 

 These limits may vary at different locations 

 but on the whole they are substantially cor- 

 rect. Back and away from the shore line, in 

 blowouts and on the sides and tops of the 

 dunes, the sound is never produced. There is 

 no observable difference between the sand lo- 

 cated near the shore and that located farther 

 back or that forming the dunes, and indeed 

 the sand which is washed up by the waves is 

 that which, blown by the wind, goes to form 

 the dunes. 



The upper beach limit of the singing sands 



about right when he said it was like that made by 

 rubbing wet glass with your finger. I thought it 

 as much like the sound made in waxing a table as 

 anything. It was a squeaking sound, as of one 

 particle rubbing on another. I should say it was 

 merely the result of the friction of peculiarly 

 formed and constituted particles. The surf was 

 high and made a great noise, yet I could hear the 

 sound made by my companion 's heels two or three 

 rods distant, and if it had been still, probably 

 could have heard it five or six rods." 



