30O TJie Ametican Geologist. November, i89!« 
not only of great theoretical import, but it has a vast practical 
bearing in all stratigraphic work. 
4. In a simple vertical section it is possible for planes of 
all four orders to coincide, but laterally in all directions, many 
of a smaller order may be included in one of the next larger. 
ERUPTION OF MAUNA LOA. 1899. 
By Edgar Wood, Honolulu. 
(Plate XIV.) 
On the morning of the 4th of July (1899), news was re- 
ceived that Mauna Loa was in eruption, that light of great 
brilliancy had been seen in the summit crater, in the very early 
morning. Later in the day the report was confirmed. The 
first appearance was about ten minutes past 3 a. m. It seems 
first to have been seen from Punalun, where a steamer was 
loading. 
From the summit crater, Makuaweowea, a column of light 
and smoke ascended into the air, to the hight of, perhaps, 20,- 
000 feet, spreading out like a vast umbrella. The people, at 
Punalun, seem to have noted no violence in the outbreak but. 
at the Volcano house, at Kilauea, the inmates tell of an ex- 
plosion of considerable violence. At first the people at the 
Volcano house looked in the direction of Kilauea where an 
eruption had been recently expected, but all was quiet there. A 
difTferent, sight, however, met the eye in turning to Mauna Loa. 
The clouds, in every direction reflected the fire. Night was 
turned into day, as the heavens were lighted up with the bril- 
liancy of the burning mountain. An observer, who had wit- 
nessed three other eruptions of the same mountain, declared 
this to be the largest and most brilliant. The reflection was 
plainly visible many miles at sea. 
During all of July 4th, the mountain was covered with 
clouds. Early in the morning of July 5th, when the clouds 
lifted, it was seen that the fire had moved, that the light was no 
longer at the top of the mountain. The lava flow had begun. 
From the side of Mauna Loa. about 3,000 feet from the top of 
the mountain, two great fountains of liquid fire threw high into 
the air immense (piantities of seething, glowing lava. The 
