Following is an abstract from a report of Dr.Bolton,H.C:
From "Trans.New York Acad.Sci.,Vol.10,28-35(1890) "
"Researches on Musical Sand in the Hawaiian Islands"
As a natural curiosity the place has a world-wide fame, but the printed accounbs
are rather meager in detail, and show their authors to have been unacquatinted
with similar phenomena elsewhere.
On the southwest coast of Kauai, in the district of Mana, sand-dunes attaining
a height of over 100 feet extend for a mile or more noorly Parallel to tho sea,
and covering hundreds of acres with the water-worn and wind-blown fragments
of shells and coral. The dunes are terminated on the west by bold cliffs (Pali)
whose base is washed by the sea; at tho east end the range terminates in a dune
more symmetrical in shape than the majority, having on the land side tho appearance
of a broadened truncated cone. The sands on the top and on the landward slope
of this dune (being about 100 yards from the sea) possess remarkable acoustic
propertics, likened to litte bark of a dog.
The dune has a maximum height of 108 feet, but the slope of sonorous sand is
only 60 feet above thc level field on which it is encroaclling. At its steepest
part, the angle being quite uniformly 31°, the sand has0 a notable mobility
when perfectly dry, and on disturbing its equilibrium it rolls in wavelets down
the incline, emitting at the same time a deep bass note of a tremulous character.
My companion thought tho sound resembled the hum of a buzz-saw in a planing
mill. A vibration is sometimes perceived in the hands or feet of the person
moving the sand. The magnitude of the sound is dependent on the quantity of
sand moved, and probably to a certain cxtent upon the temperature. The drier
the sand the greater the amount possessing mobility and the louder the sound.
At the time of my visit the sand was dry to the depth of four or five inches
; its temperature three inches beneath the surface was 87°Fahrenheit, that of
the air being' 83° in the shade (4:30 p.m.).
When a large mass of sand was moved downward I heard the sound at a distance
of 105 feet from the base, a light wind blowing at right angles to the direction.
On one occasion horses standing close to the base were disturbed by the rumbling
sound. When the sand is clapped between the hands a slight, hoot-like sound
is heard ; but a louder sound is produced by confining it in a bag, dividing
the contents into two parts, and bringing them together violently. This I had
found to be the best way of testing sea-shore sand as to its sonorousness. The
sand on the top of the dune is wind-furrowed and generally coaser than that
of thc slope of 31°, but this also yielded a sound of unmistakable character
when so tested. A bagful of sand will preserve its power for some time, especially
if not too frequently manipulated. A creeping vine with a blue or purple blossom
(kolokolo) thrives on these dunes and interrupts tho sounding slope. I found
the main slope 120 feet long at its base, but the places not covered by this
vine gave sounds at intervals 160 paces westward. At 94 paces further the sand
was non-sonorous.
The native Hawaiians call this place Nohili, a word of no specific meaning,
and attribute the sound caused by the sand to the spirits of the dead, uhane,
who grumble at being disturbed; sand-dunes being commonly used for burial placcs,
especially in early times, as bleached skeletons and well-preserved skulls at
several places abundantly show.
Sand of similar properties is reported to occur at Haula, about three miles
east of koloa, Kauai; this I did not visit. but, prompted by information communicated
by Hon. Vladimar Knudsen, of Waiawa, I crossed thc channel to the little-visited
island of Niihau. On tho western coast of this islet, at a place called Kaluakahua,
sonorous sand occurs on the land side of a dune about 100 feet high, and at
several points about 600 to 800 feet along thc coast. On the chief slope, 36
feet high, the sand has the samc mobility, lies at the same angle, and gives
when disturbed the same note as the sand of Kauai, but less strong, thc slope
being so much lower. This locality has been known to the residents of the is
land for many years, but has never been before announced in print. This range
of dunes, driven before the high winds, is advancing, southward, and has alreacly
covered tho road formarly skirting the coast.
The observations made at these places are of especial interest because they
confirm views already advanced by Dr. Julien and myself with regard to thc identity
of the phenomena on seabeaches and on hillsides in arid regions (Jebel Nagous,
Rig-i-Rawan, etc.). The sand of the Hawaiian Islands possesses the acoustic
properties of both classes of places ; it gives out the same note as that of
Jebel Nagous when rolling down the slopo, and it yields a peculiar hoot-like
sound when struck together in bag, Iike the sands of Eigg, Manchester, Mass.,
and other sea-beaches a property that the sand of Jebel Nagous fails to possess.
These Hawaiian sands also show how completely independent of material is the
acoustic quarity, for they are wholly carbonate of lime, whereas sonorous sans
of all other localities known to us (now over one hundred in number) are silicious,
being either pure silex or a mixture of the same with silicates, as feldspar.
'
In 1875 Dr. James Blake, of San Frahcisco, examined microscopically a specimen
of the Kauai sand sent him by Mr. Frink, and ascribcd its acoustic qualities
to thc cellular character of the grains. This condition, however, Dr. Julien
and I fiud to be exceptional, since most sonorous sand is quartzose, and we
believe the gaseous-film theory, already announced to the Academy, applies equally
to sonorous sand of diverse form, composition, and origin.
A speccimen carried away in a bag, and another shipped over land in a keg, have
both preserved their acoustic qualities up to data.
[ The speaker exhibited specimens, and obtained a low hoot like sound by clapping
together sand confined in a bag. The subject was also illustrated by numerous
original photogrnphs (projected on a screen) of the Nohili, and of scenery on
the island of Kauai.]