GEOGRAPHICAL PROGRESS. 



GEOLOGICAL SURVEY, U. S. 401 



coast of New Guinea as far as Huon gulf on 

 the north, and the islands Long and Rook; 

 while the groups of islands lying opposite the 

 southeastern point of New Guinea, comprising 

 the D'Entrecasteaux Islands, Woodlark, Laugh- 

 Ian, and the Louisiade Archipelago, are to be 

 henceforth in the possession of England. 



Mr. Verbeck, who was sent by the Dutch 

 East Indian Government to investigate the 

 causes and effects of the eruption of Mount 

 Krakatoa, in May, 1883, has finished and pub- 

 lished his report. Although earthquakes were 

 felt at the same time in Australia, and it is 

 'found that a seismic movement of the sea- 

 bottom in the whole region of the Moluccas 

 occurred simultaneously, yet the disturbance, 

 according to the results of the inquiry, was 

 volcanic and not seismic. The theory is that 

 large quantities of water, probably from the 

 ocean, were suddenly brought into contact 

 with incandescent matter in the neighborhood 

 of the old volcano. According to Mr. Ver- 

 beck's calculations, at least eighteen cubic kilo- 

 metres of matter must have been thrown out 

 during the eruption ; to give an idea of this 

 vast mass, " Nature " says : " Imagine a box of 

 ashes as large as Hyde Park and as high as the 

 dome of St. Paul's ; a hundred such boxes will 

 give an idea of the mass of matter thrown out 

 (by Krakatoa in 1883." It is estimated that this 

 mass of matter was thrown to a height of fifty 

 kilometres, or nearly six times the height of 

 Mount Everest. Some of the pumice thrown 

 into the sea was carried as far as the east coast 

 iof Africa; some is now to be found in the 

 Pacific between the Caroline and Marshall Isl- 

 ands ; and Mr. Verbeck thinks it will reach the 

 American coast at Panama early in 1886. The 

 Lheory of Mr. Verbeck of course presupposes a 

 3entral fire, and, according to it, the earth's 

 3rust must be much thinner than has been sup- 

 posed, an inference justified by the vast extent 

 }f the disturbance caused by the eruption. 

 The explosions were heard over an area 

 imounting to one fourteenth of the earth's 

 mrface, while the air- wave set in motion by it 

 : raveled all around the globe and back to 

 Irakatoa. It is held, also, that the great tidal- 

 vave that followed was occasioned, not by 

 mrthquake-shocks, but by the projection into 

 he sea of great masses of matter, including one 

 iide of the crater itself. 



A New Volcano. In October an immense vol- 

 5ano arose in the Pacific Ocean, latitude 20 

 51' south, longitude 175 28' west, fourteen 

 niles from the island of Tonga. Mr. H. Ship- 

 ey, United States consul at Auckland, New 

 Zealand, writing to the State Department, says : 

 ''At daylight on Oct. 13 we observed dense 

 , r olumes of steam, smoke, and clouds ascend- 

 ing. We sailed sufficiently near to see that it 

 Vas^a submarine volcanic eruption. Consider- 

 ng it not prudent to approach- any nearer that 

 light, we lay -to until morning. We then ap- 

 proached to about the distance of two miles. 

 Eruptions take place every one or two min- 

 VOL. xxv. 26 A 



utes, changing its appearance every second, 

 like a dissolving view. It was one of the most 

 awfully grand sights I ever witnessed on the 

 high seas. As to the size of the island thrown 

 up, I am unable to state correctly, there being 

 so much steam and clouds hanging over it, but 

 I judge it is at least two or three miles long 

 and sixty feet high." 



GEOLOGICAL SIRVEY OF THE UNITED STATES. 

 Geology and Exploration. Prior to the civil war, 

 the investigation by the United States Govern- 

 ment of the geology of its domain was either 

 incidental or desultory. Geologists were at- 

 tached to many important exploring parties, 

 military, naval, and civil, and in a few in- 

 stances special investigations were instituted 

 for the purpose of determining the mineral re- 

 sources of tracts of public land. 



One of the most important pieces of inci- 

 dental geologic work was that connected with 

 the. exploration of the transcontinental rail- 

 way routes. In the years 1853-'56 five lines 

 of geologic reconnaissance were thus carried 

 across the country, and these were supple- 

 mented by numerous more local examinations. 

 A similar work was performed in connection 

 with the Mexican Boundary Survey (1849- 

 1855). The surgeon of Capt. E. B. Marcy's 

 expedition to explore the Red river of u Lou- 

 isiana" (1852) was also a geologist. A ge- 

 ologist accompanied Lieut. G. K. Warren in 

 his exploration of the Dakota country (1855- 

 '57), and the same geologist accompanied the 

 succeeding expeditions under Capt. W. F. Ray- 

 nolds (1859-'60). Capt. John Pope's search 

 for artesian water on the Llano Estacado 

 (1855), Lieut. J. C. Ives's exploration of the 

 Colorado river (1857-'58), Capt. J. H. Simp- 

 son's expedition in search of a wagon-route 

 through Utah and Nevada on the line of the 

 39th parallel (1859), and Capt. J. N. Ma- 

 comb's exploration of the San Juan country 

 (1859), were all made to contribute informa- 

 tion as to the geologic structure. In 1849 the 

 naval expedition under Com. Wilkes touched 

 the Pacific coast and gave its geologist an op- 

 portunity to explore portions of Washington 

 Territory and Oregon ; and still earlier, in the 

 years 1845 and 1846, two land-surveyors, W. 

 A. Burt and Bela Hubbard, acting under in- 

 structions from the General Land-Office, gath- 

 ered information in regard to the rocks of the 

 country traversed by the township lines of 

 linear surveys in Michigan. 



In 1834 G. W. Featherstonehaugh made an 

 examination of the elevated country between 

 the Missouri and Red rivers, and in the follow- 

 ing year he traversed what was known as 

 Wisconsin Territory. His instructions came 

 from Congress through the War Department, 

 and his reports were addressed to an officer 

 of the army, but his work appears not to have 

 been subsidiary to any military purpose. In 

 1839 David Dale Owen was sent by the Gen- 

 eral Land-Office to make a geologic examina- 

 tion of the States of Iowa, Wisconsin, and 



