30 TRANSACTIONS OF THE [ocr. 27, 
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 the channel to the little-visited 
island of Niihau. On the western coast of this islet, at a place 
called Kaluakahna, sonorous sand occurs on the land side of a 
dune about 100 feet high, and at several points about 600 to 800 
feet along the coast. On the chief slope, 36 feet high, the sand 
has the same mobility, lies at the same angle, and gives when 
disturbed the same note as the sand of Kauai, but less strong, 
the slope being so much lower. ‘This locality has been known 
to the residents of the island 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 already coy- 
ered the road formerly 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 the identity of the phenomena on sea- 
beaches 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 slope, 
and it yields a peculiar hoot-like sound when struck together in 
a bag, like the sands of Higg, Manchester, Mass., and other sea- 
beaches—a property that the sand of Jebel Nagous fails to pos- 
sess. These Hawaiian sands also show how completely inde- 
pendent of material is the acoustic quality, for they are wholly 
carbonate of lime, whereas sonorous sands 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 Francisco, examined micro 
scopically a specimen of the Kauai sand sent him by Mr. Frink, 
and ascribed its acoustic qualities to the cellular character of the 
grains. This condition, however, Dr. Julien and I find to be 
exceptional, since most sonorous sand is quartzose, and we believe 
the gaseous-film theory, already announced to the Academy, ap- 
plies equally to sonorous sand of diverse form, composition, and 
origin. 
a specimen carried away in a bag, and another shipped over 
land ina keg, have both preserved their acoustic qualities up to 
date. 
[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 photographs 
(projected on a screen) of the Nohili, and of scenery on the 
island of Kauai. | 
