SCENOGRAPHICAL GEOLOGY. Jgg 



illustrate the process. Consult figures on pp. 12 and 28, and Figs. 31, 

 36, 63, 71, 72, ;9, and 82 to 86. 



An intermediate step in the process is illustrated in Fig. 71, the type 

 of a very common state of things among our high mountains. The 

 loose blocks accumulate so abundantly that most of the precipice has 

 disappeared, and the fragments assume their natural angle of thirty-five 

 degrees with the horizon, so as to render walking up the slope a matter 

 of considerable difficulty. The one who goes first disturbs the equilib- 

 rium of some loose block, and it rolls down the hill, greatly to the dis- 

 comfort of those who follow. These fragments are slaty. When granitic 

 in character, and the disintegration has proceeded further, slides often 

 result. After the rapid, thorough saturation of the gravelly mass with 

 water, it becomes semi-fluid in its properties, and great portions of it 

 slide to the bottom of the valley, often devastating fertile fields and 

 destroying lives in consequence of the suddenness of the slipping. 

 Another interesting view of the accumulation of fragments by frost 

 disintegration appears in the copy of Mr. Morse's drawing of Carrigain 

 notch. 



Sculpturing of Granitic Rocks. 



The first of the rocks, whose peculiar mineral composition gives rise to 

 characteristic scenic forms, are the Granitic. The simplest case is that 

 of a mountain like Chocorua (Figs. 31 and 61) or Pequawket (heHotype, 

 Vol. II). It is a conical mountain, with a sharp summit, and not trun- 

 cated like the volcano. Other examples are Mts. Monadnock, Ascutney, 

 and Black, near the Connecticut in Vermont. The more complicated 

 cases are where several conical peaks are grouped together. The two 

 Percy peaks in Stratford afford a very fine example, as shown in a helio- 

 type illustrating Chapter XIX. Others are the Stratford and Columbia 

 peaks, numerous eminences in Essex county, the Orange mountains 

 east of Montpelier, Vt., Profile, Tremont, and Haystack in the Saco val- 

 ley, Crawford, Resolution, Iron, and others north of the Saco, Tripyramid, 

 several others in Pemigewasset, Gunstock and Belknap, Red hill. Green 

 mountains in Effingham, Moose mountain near Wolfeborough, Iron-ore 

 hill near Haverhill, range of mountains in the west part of Benton, Mote 

 mountains in Albany, and others. 



