48 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



small gulleys. Sandstone cliffs bound it on each side. The 

 sand is of a pale yellowish color, and is so pure and fine, and 

 so perfectly dry, and at the same time lies at so high an angle 

 (nearly 30) with the horizon as to be set in motion by the 

 slightest cause. When any considerable quantity is thus in 

 motion, rolling slowly down the slope like some viscous fluid, 

 then the singular acoustic phenomenon is heard, from .which 

 the mountain derives its name at first a deep, swelling, vi- 

 bratory moan, rising gradually to a dull roar, loud enough 

 when at its height to be almost startling, and then as gradu- 

 ally dying away till the sand ceases to roll. Captain Palmer 

 states that it is difficult to describe this sound exactly. It is 

 not metallic, nor like the sound*of a bell, nor yet that of a 

 gong ; perhaps the very hoarsest note of an JEolian harp, or 

 the sound produced by rubbing the wet rim of a deep-toned 

 finger-glass most closely resembles it, except that the rolling 

 sand has less music in it. It may be likened to the noise pro- 

 duced by air rushing into the mouth of an empty metal flask 

 or bottle, sometimes almost approaching the roar of thunder, 

 and then resembling the deeper notes of a violoncello or the 

 hum of a humming-top. In the course of tw T o days' experi- 

 ments, Captain Palmer ascertained that the hot surface-sand 

 was always more productive of sound than the cooler layers 

 underneath, the hot particles appearing to run more quickly 

 than the cold. 15 A, August 19, 246. 



NEW FORM OF SENSITIVE FLxIE. 



Some of our readers are familiar with the interesting phys- 

 ical fact that certain flames are exceedingly sensitive to 

 sound, and have seen notices of the experiments of Professor 

 Tyndall and Professor Pepper, in London, upon this subject. 

 Quite recently, according to Nature, a new form of sensitive 

 flame has been devised by Mr. Barry, of Cork, which is said 

 to be the most easily affected one known, possessing the ad- 

 vantage that the ordinary pressure in a gas-main is quite suf- 

 ficient to develop it. The method of producing it consists in 

 igniting the ordinary coal-gas, not at the burner, but some, 

 inches above it, by interposing between the burner and the 

 flame a piece of wire gauze of about thirty-two meshes to the 

 inch. A pin-hole burner is used, so as to produce a conical 

 flame. 



