ERMINE 



2073 



EROSION 



ERMINE, ur'min, or STOAT, stole, the 

 name given to any weasel of cold cjimatcs 

 which turns white in, winter; it is generally 

 applied to the animal only at that time. Some- 

 times the word is used only with reference to 



THE ERMINE 

 (a) Summer coat; (b) winter coat. 



the fur. From a reddish-brown, the short, soft, 

 silky fur of this animal changes to a yellowish- 

 white in normal winter weather, or to a pure 

 while in extreme cold. The very tip of the tail is 

 always black, however. The trapping of ermine 

 requires great patience and exposure to bit- 

 terly-cold weather. Not a great many skins are 

 taken yearly; a large part of the fur now sold 

 as ermine is merely the fur of the white rabbit. 

 As an ordinary trap would tear the delicate 

 fur of the ermine, a knife-trap is used. That 

 is, an ordinary hunting knife, greased, is placed 

 in the snow to lure the animal by its resem- 

 blance to ice, which it seldom fails to lick. At 

 very low temperature the tongue of the little 

 animal freezes to the steel blade, and the 

 hunter easily secures his victim. It is esti- 

 mated that to the trapper ermine pelts, sold in 

 quantities, bring from 30 cents to $2.50 each, 

 but that is before the expensive process of 

 dressing has been applied. When all ready for 

 use, a stole of the softest, whitest ermine often 

 commands as high as $1,000, for one pelt is 

 only about twelve inches long, and one com- 

 mercial fur requires many young ermine. The 

 best skins are secured in Northern Canada, 

 Russia, Sweden and Norway. Ermine is used 

 for neck pieces, muffs, trimming of various gar- 

 ments, linings of coats and for trimming robes 

 of judges. It is an emblem of royalty, and 

 various ranks of nobility were at one time 

 designated by the arrangement of the black 

 tail-tips. 

 E'ROS. See CUPID. 



EROSION, cro'zhun. If we examine the 

 slopes of a cut along a railway or where a road 

 has been graded, we find a large number of 

 little ruts in them. When the cut was made 

 these slopes were smooth. How were the ruts 

 formed? Let us study the slope during a 

 shower. We soon discover little streams run- 

 ning down the ruts, and we also notice that 

 each stream is carrying some of the earth along 

 with it, so that each succeeding shower makes 

 the nits larger, until, in time, they may become 

 tiny valleys. This wearing away of the land 

 by water or any other agency is called by 

 geologists erosion. Erosion is caused by rain, 

 by running water, by wind and by ice. 



Rain. Rain water contains small quantities 

 of ammonia, nitric acid and sometimes muriatic 

 acid. These substances decompose the rocks 

 upon which the rain falls, and thus, form sand 

 or soil which the rain may carry to lower 

 levels. Although this decomposition of the 

 rock is very slow, in the course of ages it 

 causes important changes on the earth's sur- 

 face. 



Running Water. We have shown how run- 

 ning water wears away the land on a small 

 scale. Now in place of the tiny stream formed 

 by a shower, let Us consider a mountain stream 

 and a river. As the stream flows down the land 

 slopes it gathers speed, and flows much faster in 

 the lower part of its course than where it be- 

 gins. This increase . in speed gives the water 

 increased power, so it wears its channel more 

 rapidly in the lower than in the upper part 

 of its course. It also carries heavier and 

 coarser material. Hence we find that valleys 

 formed by mountain streams increase in depth 

 as they extend down the slope, and because 

 the lower part of the valley is formed rapidly 

 its sides are usually steep. 



Large rivers usually flow over more gentle 

 slopes, and form wide valleys with gently- 

 sloping sides. Moreover, the river carries down 

 much of the fine soil and sand brought to it 

 by the numerous mountain streams. As it 

 reaches the lower levels it deposits this ma- 

 terial on its bed and banks and at its mouth, 

 where it may form great deltas, like those at 

 the mouth of the Mississippi. The low, flat 

 land along river banks is formed in this way. 

 Some of the grandest features of natural scen- 

 ery are the result of river erosion. The Grand 

 Canyon of the Colorado and the Canyon of 

 the Yellowstone were formed in this way. 



Influence of Forests. Rain falling upon 

 bare slopes strikes the ground with greater 



