148 



SCIENCE 



[N. S. Vol. XLII. No. 1074 



continued through October very much as in 

 October, 1912. In November there vras a rise, 

 accompanied by flows of lava from the glow- 

 ing cones, so that in December there was a 

 floor of black lava 200 feet long and 150 feet 

 ■wide, at a depth of about 580 feet. 



From the last of November, 1913, until 

 March, 1914, conditions remained very much 

 the same, with no more flows, but with a glow 

 most of the time. Molten lava was ejected 

 Ifrom the Old Faithful orifice to a height of 

 40 feet on March 6, and there was a short flow 

 the next week. The next flows reported came 

 in the early part of May, with a pool 25 feet 

 in diameter at Old Faithful. This period of 

 activity continued until the middle of June, 

 when the floor had attained a depth of 530 

 ■feet. After the summer solstice, until July 26, 

 there was a slower rise, with fewer flows than in 

 May-June. From July 27 until August 5 a 

 •subsidence caused a collapse in the floor. An 

 increase in activity caused a long flow on Au- 

 gust 28, but there was no permanent increase 

 until October 2, with a collapse of the Old 

 Faithful cone the next day, forming an open 

 pool 40 feet in diameter. On October 4, the pool 

 had become triangular in shape, 100 feet long 

 and 70 feet wide. The next day the pool was 

 200 feet long and 100 feet wide, with a depth 

 below the rim of about 470 feet. By October 

 13 the pool had become 600 feet long, but was 

 28 feet lower. The subsidence continued, with 

 the caving of the walls, until the twenty-sec- 

 ond. On October 21, the lava was 518 feet be- 

 low the rim, and on the twenty-third the lake 

 was 375 feet long, 150 feet wide. From this 

 date until November 6, the lake rose, and a 

 flow 450 feet long came from a cone on the 

 western corner of the floor. On November 16 

 the line of northeast cones and three north- 

 west cones were engulfed in the lava, forming 

 a northeast arm on the main lake and a sepa- 

 rate northwest pond. The length of the lake 

 was estimated, on the I7th, to be 400 feet, the 

 east arm 150 feet long, the northwest pond 100 

 feet long, and a new northeast pond 12 feet 

 long. The depth of the lake was about 469 

 feet. Three flows had developed along the 

 floor; one from an east-border pot southward, 



one from the end of the new east arm north- 

 ward, one from the north side of the north- 

 west pond northward. The length of these 

 flows was about 100 feet each. 



The week preceding the outbreak of Mauna 

 Loa witnessed a slightly less active condition 

 in the Halemaumau lake than during the pre- 

 vious week. On November 19 the lake was 460 

 feet below the rim, with the current running 

 from the west into the east arm. The east arm 

 and the northwest pond were enlarged by col- 

 lapse of the sides. TJntil December 1, the lake 

 remained from 5 to 30 feet below the level of 

 the floor, with daily fluctuations of level, 

 reaching a maximum height about noon. 

 Streaming, traveling fountains, and caves 

 against which the lava splashed with surf 

 noises were of common occurrence. 



On December 2, two fresh flows were ob- 

 served on the floor; one had come from the 

 west end of the pit and spread along the west 

 and north margins, the other from near the 

 east cove and spread northward. The north 

 boiling pot had enlarged almost to a small 

 pool. On December 4, there was a small flow 

 on the north side of the pit, glowing and hiss- 

 ing cones on the west floor and in the south- 

 west talus, and a small splashing at the south- 

 east cone. There was a collapse of the floor 

 on the north side of the pit, leaving what later 

 developed into a rising crag between the main 

 lake and the northern floor. On the fifth and 

 sixth spurts and flows of lava came out of the 

 west cones and a cone 50 feet up on the 

 southwest talus. The flow from the west cones 

 on the sixth covered the whole southwest border 

 of the floor, 500 feet in length. In the main 

 lake, a torrent was pouring from the east arm 

 into the main pool. On December 7 a further 

 collapse of the floor area on the north pro- 

 duced a trench between the east arm and the 

 northwest pond, the floor block between this 

 trench and the lake being raised and tilted 

 toward the lake to produce what will be called 

 the " crag." A slight drop in the level of the 

 lake the next day showed a promontory be- 

 tween the crag and the east arm, almost cut- 

 ting off the latter. By December 9, the crag 

 had risen on the north side 58 feet above the 



