feet in thickness and looks as if they would last for many years to come. [ill. Bk22, p.773 or p.-78 A] No vegetation has secured a foothold on them. Great quantities of the fine dust were deposited on the upper slopes of the mountain and on the rim of the crater. Estimates of the amount would be mere guesses but it is evident that the rim at the point where the railroad trail reaches it retains a bed from three to eight feet thick which is composed principally of this material. Toward the northwest the increase elevation of the rim is maintained in varying degree partly with the mud and partly with coarse sand, the latter predominating. Toward the southeast and east as far as the southern limit of the crater the mud is the chief deposit on