PREFACE XI 



ears, and His work bein,^ carried on under his eyes, he cannot 

 but live always as much in realization of things unseen as of 

 things seen : — 



''' How all the moving phantasies of things, 

 And all our visual notions, shadow like. 

 Half hide, half show, that All-sustaining One, 

 Whose bibles are the leaves of lowly flowers, 

 And the calm strength of mountains : rippling lakes ; 

 And the irregular howl of stormful seas, 

 Soft slumbering lights of even and of morn. 

 And the unfolding of the star-Ut gloom." 



The geology of Tierra del Fuego is an impressive study. 

 According to Darwin, than whom no better authority has 

 arisen in all this time, the northern and eastern portion is 

 composed of horizontal tertiary strata, fringed by low, irregular, 

 extensive plains belonging to the boulder formation, and made 

 up of coarse unstratified masses, sometimes associated with fine, 

 laminated, muddy sandstones. Alluvial gold occurs freely ; 

 also lignitic coal at Cheena Creek and on the south coast. 

 In San Sebastian Bay, the cliffs are composed of fine sand- 

 stones often in curvilinear layers, including hard concretions of 

 calcareous sandstone, and layers of gravel. Towards the interior 

 of the island, the tertiary formation is bounded by a broad 

 mountainous band of clay slate. The rock forming the summit 

 of Nose Peak is determined by Dr. J. S. Flett as a fine, highly 

 felspathic grit, yellow in colour when weathered and soft from 

 the abundance of felspar. It consists of quartz, various felspar, 

 fragments of slate or shale, biotite decomposing to chlorite, 

 and a minutely fragmental interstitial or cementing material. 

 Metamorphic schists, granite, and various trappean rocks compose 

 the western and broken portion. No recent volcanic district 

 occurs anywhere. The clay slate is generally fissile, sometimes 

 siliceous or ferruginous with veins of quartz and calcareous 

 spar ; often assuming, especially on the loftier mountains, an 

 altered felspathic character, passing into felspathic porphyry; 



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