Arizona weekly citizen., 1890-09-13
A SAND THAT BARKS.
AN ACCOUNT OF THE MUSICAL EARTH
 OF THE SANDWICH ISLANDS.

| the Oiobe's Hakeup-BTusicaI Sand Ls Found in Several COuntries-SOme Hy-
 POtheses to Explain the Cause.
 The so-called barking sands'' ofKausi
 are mentioned in the works of several travellers In the Hawaiian islands. and have worldwide fame as a natural curi- oslty. As rule, however, the printed ac- counts are meager in details, and show the authors to have been Unacquainted with similar phenomena elsewhere.
 Jointly with Dr. Alexis A. Julien, of
 Columbia college, New York, I have been
 studying the properties of sonorous sand
 for long time, and have visited many
 localities in America, Europe and Asia;
 hence was able during a recent visit to
 Kauai to make some notes and conpari.
 sons that may interest the residents of
 this kingdom.
 Notwithstanding recent rains found
 the sand on the dune at Mana dry to the
 depth of four or five inches, and when
 pushed down the steep incli1ss it gave out deep base note having a tremulous character. This hardly resembles the
 barking" of a dog, but a sound some
 what like it is produced by plunging the
 hands into the sand and bringing them vigorously together. Another way is to till long bag three-quarters full of sand.
 and then dividing its contents into two
 parts, holding one in each hand, to clap
 the two portions together. This I had
 found to be a good method for testing the sOnOrousness of sand on sea beaches. A bag of the sand will preserve it's acoustic qualities a long time if kept dry and not too frequently manipulated. The angle at which the sand lies where It falls over the dune i 31 degrees; the fonOrOUsness extends several hundred feet along the dune, being interrupted
 by a creeping vine that thrives marvel. OUaly iu such soil.
 A similar dune of sOnOrOus sand Oc- GUS ol NnlaU, as has long been known to residents Of the island. and it has been also reported to occur near Kobe.
 These observations, simple as they are. have been of special interest to me. be- cause they show that the sand of these localities forms link between that of the Sc be- c.:=s and that of @ certain hill on the GU-f of Suez known as Jebel Na- gous. ans, which l visited in April, 1889. SOnOrous sand is of more common occur renee than generally sup Osed It is found on the Ati2n-ic coast of the Unit ell States from 143li3 to Florida, on ths Pacific cCast. in Europe, Japan, Africa. Tasmania. etc., as well as on the shores of many fresh water iazes. n these localities 1t forms aresIs gelar..lty between low tide and the blseCI adjoining dunes, and einits sounds only when subjected to friction by the feet and hands or int bag as described. At Jebel Nagous. r Arabia, on the other hand, the sand rests in ravine, and prOiuces sound only when 1t rolls down the incline (which it often does spoIiaEe0usiy)a and fails to rs- spord to kicks aud cuffs.
 The sand as Mana. as shown. unites in itself both these acoustic properties. The angle at which the sand lies at Jebel NagOCs Is the same as at Mana, S1 de- grees being the angle of rest for fne dry sand. Tie musical notes obtained at these far separated localities are also the same, but in Arabia the incline is 39O feet high, and consequently the sounds are far louder, especially as they are further magIiied by being echoed from adjoining cliffs.
 The sand at Kauai and Niihau is made up of fragments of shell and coral, while that of all other localities known to us lover 100 in numbeT) is sihceous. This shows that the sOnorOusness is inde- pendent of material Examination under the microscope further shows that the quality is not connected with the shape of the grain.
 SOnorous sand Is distinguished by being free from fine dust or silt; the in- dividual grains are very uniform in size. It is very easy to deprive sand of it's acoustic power by mixing little earth with 1t or by wetting it. It is difficult if not impossible, to restore to sand its quality when once killed"
 A number of hypOtheses have been to explain the cause of this cu- nous property of certain sands. Tho prevalent idea in these islands that the sound Is due to the cellular structure of .he sand must be abandoned, since most OnOrOuS sand Is not so constituted, that # Kauai forming an exception. Some nave attributed the SOnorous quality to aline crustS, others to electricity, effer- 'escence of air between the particles, everberatiOn within subterranean cav- ties and to solarizatiOn, and one author attempts to explain the phenomena by writing of ga redUpicatiOn of impulses citing air in vibration in a focus uf chO."
 These theories Dr. Julien and reject or reasons cannot here detail, and we eheve the true cause of sonorousness to e connected with thin policies or films f air or of gases thence derived, depos- ted and condensed upon the surface of be sand grains during gradual evapora- ion after wetting by seas, lakes or rains. y virtue of these films the sand grains ecome separated by elastic cushions of ondensed gases, capable of considerable whose thickness we kaye ap- roximately determined. The extent of he vibration and the volume and pitch the sound reduced we also find to be Irgely dependent upon the forms, struct- res and surfaces of the sand grains, and specially upon their purity or freedom -om fine silt or dust.
 We have shown that the pitch of the lusical notes obtained on sea beaches ia roportional to the mass of sand moved le greater the mass the lower the tones. p the dunes of Kauai and Niihau the Ilne holds true.-H. Darlington Bolton, b. D., in Honolulu Commercial Adver- ser.
 Audible.
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