Mound-builder's 

 Movement 



SCIENTIFIC SIDE-LIGHTS 



ence at the base, with a level area at the 

 summit of one hundred and fifty feet in cir- 

 cumference; . . . these works, and 

 many others which might have been quoted, 

 indicate a population both large and sta- 

 tionary; for which hunting cannot have 

 supplied enough food, as it has been esti- 

 mated that in a forest country each hunter 

 requires an area of not less than 50,000 

 acres for his support; and which must, 

 therefore, have derived its support, in a 

 great measure, from agriculture. AVEBURY 

 Prehistoric Times, ch. 8, p. 259. (A., 1900.) 



2273. MOUNTAIN ENGULFED IN 

 EARTH Earthquake in Java Truncation of 

 a Lofty Cone. In the year 1772, Papanda- 

 yang, formerly one of the loftiest volcanoes 

 in the island of Java, was in eruption. Be- 

 fore all the inhabitants on the declivities of 

 the mountain could save themselves by 

 flight, the ground began to give way, and a 

 great part of the volcano fell in and disap- 

 peared. It is estimated that an extent of 

 ground of the mountain itself and its imme- 

 diate environs, fifteen miles long and full six 

 broad, was by this commotion swallowed up 

 in the bowels of the earth. Forty villages 

 were destroyed, some being engulfed, and 

 some covered by the substances thrown out 

 on this occasion, and 2,957 of the inhab- 

 itants perished. . . . This catastrophe 

 appears to have resembled, tho on a grander 

 scale, that of the ancient Vesuvius in the 

 year 79. LYELL Principles of Geology, bk. 

 ii, ch. 29, p. 493. (A., 1854.) 



2274. MOUNTAIN SLOWLY SINKING 



Wider Prospect from Neighboring 

 Heights Earth's Crust Changing Now. 

 Two examples of rapid earth-movement are 

 taken from Professor Rossi's " Meteorologia 

 Endogena." Professor D. Seghetti, writing 

 to Professor Rossi, says that a few lusters 

 ago (one luster = twenty years) Mount S. 

 Giovanni hid the towns Jenne and Subiaco 

 from each other. From Subiaco the church 

 at Jenne is now visible, which a few years 

 ago was invisible. The people at Jenne also 

 can see more than formerly. The supposi- 

 tion is that the side of Mount S. Giovanni is 

 lowered. This fact corresponds to a fact 

 stated by Professor Carina, who says that 

 forty or fifty years ago from Granaiola you 

 could not see either the church of S. Maria 

 Assunta di Citrone or the church of S. Pietro 

 di Corsena. Now you can see both. MILNE 

 Earthquakes, ch. 21, p. 351. [A. 1899.] 



2275. MOUNTAIN-BUILDING A LONG 

 AND COMPLICATED PROCESS Extends 

 through Ages (Ps. xc, 2). Mountain chains 

 may be regarded as cicatrized wounds in the 

 earth's solid crust. A line of weakness 

 first betrays itself at a certain part of the 

 earth's surface by fissures, from which vol- 

 canic outbursts take place; and thus the po- 

 sition of the future mountain chain is de- 

 termined. Next, subsidence during many 

 millions of years permits of the accumula- 

 tion of the raw materials out of which the 



mountain range is to be formed; subsequent 

 earth-movements cause these raw materials 

 to be elaborated into the hardest and most 

 crystalline rock-masses, and place them in 

 elevated and favorable positions; and lastly, 

 denudation sculptures from these hardened 

 rock-masses all the varied mountain forms. 

 Thus the work of mountain-making is not, 

 as was formerly supposed by geologists, the 

 result of a simple upheaving force, but is 

 the outcome of a long and complicated series 

 of operations. JUDD Volcanoes, ch. 10, p. 

 300. (A., 1899.) 



2276. MOUNTAINS AS A DEFENSE 

 AGAINST EARTHQUAKES Shocks Limited 

 by Mountain Ranges. All earthquake dis- 

 turbances have probably a tendency to radi- 

 ate in a uniform manner from their source, 

 and are only prevented from doing so by 

 meeting with heavy mountainous districts, 

 which by their mass and structure absorb 

 the energy communicated to them. Much 

 energy is also lost by emergence on the open 

 flanks of a range of mountains. Rather 

 than say that high mountains often bound 

 the extension of an earthquake, or that 

 earthquakes appear to run along the flanks, 

 of such mountains, we might say that earth- 

 quakes have boundaries parallel to the strike 

 of the rocks in a given district, that such 

 a direction is the one in which the propaga- 

 tion is the easier. MILNE Earthquakes, ch. 

 12, p. 230. (A., 1899.) 



2277. MOUNTAINS OF ETERNAL 



LIGHT At the lunar poles (where, more- 

 over, we see neither snow nor ice) there 

 are mountains so strangely situated that 

 their summits know no night; the sun 

 never sets on them. They may be called 

 the mountains of eternal light. FLAMMA- 

 RION Popular Astronomy, bk. ii, ch. 4, p. 

 123. (A.) 



2278. MOUNTAINS PILED BY VOL- 

 CANIC ERUPTIONS Caverns Hollowed be- 

 neath the Earth Earthquakes Due to Col- 

 lapse of Caverns. By the ejection of ashes, 

 and lava from volcanic vents an extensive 

 evisceration of the neighboring ground might 

 be expected. When we look at a volcano like 

 Fujiyama, nearly 13,000 feet in height, and 

 at least fifty miles in circumference, and 

 remember that the mass of cinders and slag 

 of which it is composed came from beneath 

 the area on which it rests, the point to be 

 wonderered at is that earthquakes, conse- 

 quent on the. collapse of subterranean hol- 

 lows, are not more frequent than they are. 

 At the time of a single eruption of a vol- 

 cano the quantity of lava ejected amounts 

 to many thousand millions of cubic feet. 

 In 1783 the quantity of lava ejected from 

 Skaptar Jokul, in Iceland, was estimated 

 as surpassing " in magnitude the bulk of 

 Mont Blanc." . . . Beneath a volcano 

 it is probable that viscous material imme- 

 diately takes the place of that which is 

 ejected, and that hollows are not formed 

 as in the case of chemical degradation. If 



