572 



POPULAR SCIENCE MONTHLY. 



ascent is enough to wear out a pair of shoes. 

 The snow is rarely more than a few feet 

 deep, but is cut up on the surface into num- 

 berless rough, wedge-shaped teeth, and is 

 constantly dissolved at the bottom by the 

 wai-m ashes beneath it. " Nothing like cre- 

 vasses occur in the snow, and the yawning 

 chasms reported by travelers or would-be 

 travelers can be set down as purely imagi- 

 nary." The approach to the crater was 

 signalized by a strong odor of hydrogen sul- 

 phide that filled the air. The crater is about 

 two thousand by thirteen hundred feet in 

 diameter, and from eight hundred to fifteen 

 hundred feet in depth, with nearly perpen- 

 dicular walls from which jets of steam come 

 hissing and sizzling, and rocks of various 

 sizes ai'e continually falling and plunging 

 with a roar to the bottom. This bottom 

 is heaped unevenly with debris of various 

 sorts and colors ; and, as Mr. Farrington had 

 to look down into it with a wind so fierce 

 that it caused the very walls to tremble, its 

 aspect was dismal enough. There is none of 

 the heat and movement usually associated 

 with volcanic eruptions, for that phenomenon 

 here is very mild indeed. Various parts of 

 the crater rim have been named the Pico 

 Mayor, or highest point ; ^l Fortezueh, or 

 Little Door ; El Espinazo del Diablo, or 

 Devil's Backbone ; and El Malacate, the 

 windlass, where the sulphur gatherers are let 

 down. The layers of lava of which the walls 

 of the crater are made are plainly visible at 

 intervals, dipping at various angles. 



A New Theory of Geyser Formation. — 



At a recent meeting of the Physical Society 

 at Eton College, Prof. T. C. Porter discussed 

 a new theory of geyser formation, which is re- 

 ported as follows in the Chemical News : " The 

 theories of Bunsen and others fail to explain 

 why the geyser throat appears almost com- 

 pletely full at the end of an eruption. This 

 immediate refilling is the more remarkable 

 when it is remembered that some of the 

 geysers of the Yellowstone region discharge 

 a million and a half gallons at each eruption, 

 and that the eruptions may occur at five- 

 minute intervals. Moreover, the theories 

 generally accepted assume steeper tempera- 

 ture gradients than those in a region like 

 Yellowstoue. Professor Porter suggests that 

 the phenomena are better explained on the 



assumption of an arrangement of strata such 

 as exists in artesian-well districts ; the throat 

 or shaft of the geyser being in the position 

 of a well communicating with a subterranean 

 stream — the ' tube ' of the geyser. From the 

 disturbed nature of the region, the tube of 

 the geyser follows a waved course. The 

 ' shaft ' rises from the crest of the terminal 

 wave; the other crests may be steam traps. 

 Since a basinlike formation is characteristic 

 of all geyser regions, it is fair to assume that 

 the end of the tube remote from the shaft 

 has an outcrop in the hills that form the 

 sides of the basin. By means of this out- 

 crop, water continually flows into the tube. 

 Where the tube does not sink deeply enough 

 to attain the temperature necessary for the 

 generation of steam, a quietly flowing hot 

 spring is the result. But if at any point the 

 tube descends to underground temperatures 

 sufiiciently great, steam is formed, and is 

 trapped at the highest point of a bend. 

 Ultimately this steam checks the flow of 

 water, until the accumulated head of cool 

 water from the hills overcomes the resist- 

 ance, condenses the steam, and re-establishes 

 liquid continuity. Urged by the pressure 

 behind it, the steam is impelled toward the 

 geyser throat ; it forces the hot water before 

 it until equilibrium is once again restored in 

 the tube." 



Materials for Paper Making. — One of the 



most important considerations in the selec- 

 tion of materials for paper making is that of 

 the structure of the fiber. The most perfect 

 spinning fibers, and the best for paper mak- 

 ing, are cotton and flax. They differ in that 

 cotton — unique in that respect — occurs in 

 the form of ultimate fibers and is a spinning 

 unit, while flax is composite, or a bundle of 

 ultimate fibers or spinning units. Next to 

 flax are rhea, inferior on account of the ir- 

 regularity of its fibers ; hemp and jute, which 

 have distinct qualities. After these are the 

 fibers used in twine and rope making, but 

 not adapted for spinning. All may be used 

 in paper making, with various results in the 

 quality of the product. Another important 

 item bearing upon paper material is the 

 chemical composition of the fiber, or its ca- 

 pacity of resistance to the natural agencies 

 of destruction. This is the living question 

 in modern pajier making. In this point cot- 



