n 4 FROM AN EASY CHAIR 



a height of 10,000ft. in those mountains. Where those 

 shells now are was the bottom of the sea at a compara- 

 tively recent date, probably not more than fifty million 

 years ago ! And not only have the Alps been raised 

 since then from the sea level to 15,000ft. (the height of 

 Mont Blanc), but the huge mountain valleys and the 

 great chasm of the Rhone Valley many miles wide, with 

 its floor thousands of feet below the mountain ridges, 

 have been scoured out. Deeper and wider it has gradually 

 become as it has taken shape, whilst the mountain sides 

 have been removed first by water and later by ice by 

 the great glacier consisting of solid ice, miles wide and 

 a thousand and more feet in thickness. The water no 

 longer fills the valley in solid form, but once again 

 rushes along as an irresistible torrent, tearing and wearing 

 the rock without rest or mercy, carrying it off by thou- 

 sands of tons day by day, year by year, to the plains 

 of Provence and the deep floor of the Mediterranean 

 Sea. 



The blue colour of the glacier ice like that of pure 

 water is now known to be due to no impurity or ad- 

 mixture of other substances. It does not, as was sup- 

 posed by Tyndall, owe its blueness to a dust of finest 

 colourless particles as do blue smoke, the blue sky, and 

 as do the blue eyes which have attracted the observation 

 of naturalists (and others) in Ireland and the North of 

 Europe. Water, whether liquid or solid, is blue, just 

 as " blue copperas " is, or as " Prussian blue " is ; but 

 light must pass through some ten or twenty feet thick- 

 ness of it to make the colour evident to our eyes. The 

 green tint is due to an admixture of yellow, the exact 

 cause of which is not quite easy to discover. Probably 

 it is due to minute quantities of earthy matter mixed 

 with the surface snow. 



The pressing of the high-lying snow, so as to form 

 solid ice or " glacier," is concerned with the same pro- 

 perty of snow as that which enables us to make snow 



