February 35, 1887.] 



SCIENCE. 



181 



Immediately after the disappearance of the 

 lava in Kilauea in March last, Prof. W. D. Alex- 

 ander, chief of the trigonometrical survey of the 

 Hawaiian Islands, directed his assistants to make 

 a plan of the disturbed region ; and by his kind- 

 ness we are permitted to present it to the readers 

 of Science. The triangulation and details of the 

 sunken portion are from the surveys of J. S. 



between the large and small calderas. Captain 

 Button copied these errors of Brigham into his 

 report. 



Commodore Wilkes prepared a map of Kilauea, 

 delineating the main topographical features, and 

 especially showing the ' black ledge,' — a shelf of 

 desiccated lava from 600 to 2,000 feet in width, 

 and about 660 feet below Uwakahuna, the 



AlLEleyations are referred to ik& 



floorofthe VoUa.noHou,eVer<in<ia.a.i 

 datum, ikal Uiy^iO^ia'aLyl^eaUvUc 



Wi,,Jed^ 





The CRATER OF 



KILAUEA, 



Sc<Je/ ■ 10.000 



... »J ,.... .,. 4^ 



^limih 





Gray^C 



TriangulaiioTi andffetaUs of Sunken. Portion, 

 are/rom. Survey ofAorlC^ 1836, Ij XS-Emenon- 

 dfthxHaWaccan Gofemmerd Su ryey. Oui~ 

 lines of KUauea. andike SmaU C raters /ron. 

 WmJ'.Brijlcm's Sun-ej cf IS6S. 



Emerson ; the general outlines are from W. T. 

 Brigham's survey of 1865, whUe the map was 

 drawn by F. S. Dodge. The descriptive lettering 

 is mostly taken from Brigham, with a few addi- 

 tions and improvements : for instance, the names 

 of the small adjoining craters are altered to cor- 

 respond witb Hawaiian usage. The ' Kilauea Iki ' 

 of Brigham is changed to 'Keana Kakoi,' and 

 ' Poli-o-keawe ' is changed to ' Kilauea Iki.' The 

 designation ' Poli-o-keawe ' is applied to the shelf 



highest point in the rim on the western side. It 

 encircles a lower pit, 12,000 feet long, 3,000 feet 

 wide, and 384 feet deep, which represents the di- 

 mensions of the block of melted lava that broke out 

 twenty-seven miles distant, and then flowed twelve 

 miles to the sea at Nanawali. The black ledge 

 was still discernible in 1865, but has not been men- 

 tioned for the past ten years. The southern end 

 of the deep pit represents the centre of activity, 

 called ' Haleraa'uma'u.' From time to time tem- 



