516 Scientific Intelligence. 
bottom of the slates is ge 6 the dome — prevails almost 
to the exclusion of others. As w proceed southward or north- 
ward along the chain eo the region He is cent to Yosemite Valley, 
dome forms gradually ya less perfect. 
inter forms already conceived and ripe. The harder the rock, ang~ 
the better its = alized cleavage planes are developed, thy 
greater will be the degree of controlling power possessed by 14 
over its ree roe as compared with that of the disinterring gla- 
- and the softer the rock and more —* developed its 
8 
cier, gliding with tremendous pressure past splitting precipices 
and. smooth-swelling domes, flexible as the wind, yet hard-tem pered 
Maes is 4. 
2. Note on = recent Volcanic Action in Hawaii ; by T. Coan. 
from a letter to J. D. Dana, dated Hilo, Hawaii, Jan. 6th, 1874.— 
bug are oar that the great summit crater of Mauna Loa, 
strations, which roused the attention of m witnesses. But it 
was not until the 20th of April, 1873, that a continuous exhibi- 
tion of mountain pyrotechnics commenced. From that day to 
the present, now almost nine months, the action within the great 
cauldron has not remitted. Most of the time the boiling has been 
vehement, and the scene was never more brilliant than a few 
5 pa 
ings and roarings ae been heard low down the a oF the 
moun ages and, as some testify, as far as Reed’s Ranch, probably 
fifteen miles. 
__ But the great marvel of this eruption is its duration. We have 
_ Seen nothing like it before in this crater. The eruption of 1855-6 
