242 STRATIGRAPHICAL GEOLOGY. 



nearly opposite Fig. 22. The stone is rather triangular in shape. The figures refer- 

 ring to the lines of curvature will be found placed to agree with the description. 

 Owing to a slight change in the position of the stone, the top view is more extensive 

 than as originally described. What is called the shorter fault is the one nearest the 

 letter A, the changed position permitting its representation larger than at first seen. 

 We can also see the smaller fault of the side view at its beginning on the top. The 

 letters A, B, and C indicate where the edges of the adjacent sketches join each other. 

 Every side is rejjresented. The two faults do not seem to join on the lower side, but 

 to approach near each other and then diverge again. The black crystals seen all 

 through the layers are of hornblende.] 



[Description of Heliotypes. Since the printing of the account of the Franconia 

 breccia along the Portland & Ogdensburg Railroad and the Flume upon Mt. Willard, I 

 have had heliotypes taken to illustrate them, and placed opposite this page. The ce- 

 ment of the fragments is the "Breccia granite" described upon page 169; and the 

 ledge photographed is a rock cutting where the railroad makes a sharp turn westerly, 

 nearly at the northern limit of the Conway granite. The large fragments so well 

 shown are the Montalban schists, fractured by lateral pressure, and cemented together 

 without removal by transportation. A reexamination of the breccia of the same appar- 

 ent age at Franconia indicates the cement there to be very much like this in the Notch. 



The larger flume described on page 172 is represented on the other side of the helio- 

 type. The view was taken from the inside, near the top, looking out towards Mt. 

 Webster. It is impossible to obtain any photograph that will adequately represent the 

 whole of the chasm. The name of the discoverer was first applied to this interesting 

 cleft in the ledge by a large party of tourists from Massachusetts, shortly after the 

 description of its geological character on the aforementioned page had been written. 



Another double heliotype illustrates Mt. Crawford and the Lake of the Clouds (p. 

 182). The first represents the appearance of Mt. Crawford from the hill back of Dr. 

 Bemis''s house. Most of the precipitous slope visible is composed of Conway granite. 

 Glen Crawford appears at the extreme right. The rock at the Lake of the Clouds is 

 the common andalusite mica schist of the main White Mountain range. The ice still 

 partly remained when the negative was taken, in the month of May, on account of its 

 great altitude — 5000 feet. 



Several of the heliotypes have been colored to show the distribution of the forma- 

 tions. It is not possible at this time to say what these colors are ; but it is hoped that, 

 by comparing the heliotypes with their descriptions, the significations of the several 

 tints will be perfectly understood. One is the view of Mt. Willard, noticed upon page 

 177. The other view upon the jMate represents a mass of breccia granite, situated in 

 the midst of Montalban schists, in the Silver Cascade. The colors of the Mt. Pequaw- 

 ket heliotype may be explained by studying page 236. The Mt. Chocorua heliotype is 

 spoken of upon page 232. The double plate showing the Eagle Cliffs of Franconia 

 breccia, by the side of Pemigewasset granite, is noticed upon page 139.] 



