434 J. D. Dana—Changes in the Mt. Loa Craters. 
much importance. In my Geological Report I endeavored to 
bring the history in a brief way down to 1849, the time of its 
publication. Mr. Brigham reviewed the same to the date of 
his last examination in 1865. 
Captain Dutton gives his own observations in 1882, and his 
conclusions, with a few citations from other accounts; but the 
condition of the crater at the time of the visit was not favor- 
able for an appreciation of the phases of the voleano or for an 
understanding of all its phenomena; and he is led to doubt 
much that was well reported before him, very much more than 
appears, in the light of the facts presented beyond, to be rea- 
sonable. 
The conclusions he gathers from the accounts, as stated on 
pp. 117, 118 of his Report, are the following: 
“At the present time [1882] the liquid lava columns stand about 
435 feet higher than they did forty years ago. No record has 
ever been kept of the progressive action by which these changes 
have been brought about. Nothing remains to show the succes- 
sive steps In the accretion of lavas which gradually filled up the 
interior pit. The only guides we have are the fragmentary 
accounts of numberless visitors describing the condition of Ki- 
lauea from time to time. These are all so incoherent, and so 
grossly wanting in precision, that it is impossible to frame a con- 
nected account of the process. 
“There are, however, a few general features of the process 
which appear, and these may be briefly summarized. All accounts 
go to show that the height of the liquid column oscillates in an 
irregular manner; and while most of these oscillations are small, 
usually not exceeding ten to fifteen feet, yet in exceptional cases 
they are very much greater. Whenever the liquid column rises 
there is a tendency to overflow the margin of the pool which sur- 
rounds it, and this frequently happens. The quantities of lava 
thus outflowing and spreading out over a considerable area vary 
extremely, being sufficient sometimes to cover no more than a few 
acres to the thickness of a very few feet, while on rare occasions 
a square mile or two may be overflowed with a considerable body. 
The duration of these overflows is also extremely variable. Some- 
times it is a single belch or surge lasting but a few minutes. It 
is quite common for the lava to run in this way for a whole day, 
and in large outflows it may run for two or three weeks without 
interruption. Sooner or later the liquid column sinks and the 
overflow ceases. The eruptions are not by any means confined to 
the lakes, but break out at unexpected places. One of the most 
favored spots for this action is the former focus of the Old South 
Lake, which for several years has been completely frozen over. 
The cooling lava invariably takes the form of pahoehoe.” 
The above meagre summary, which Captain Dutton’s facts, 
and his knowledge of the descriptions of earlier “ visitors,” 
