CHAP. XXIII. THE MINGAN ISLANDS. 47 



clmrt, or in the local attraction on board the vessels 

 themselves.' The loss of the North Briton steam- vessel 

 has been attributed to the local attraction of the magnetic 

 iron ore on the coast ; but not only does the testimony of 

 Admiral Bayfield militate against this view, but the proper 

 sailino; direction of the vessel would not brinoj her within 

 twice or thrice the distance mentioned by Bayfield as 

 within the limits of attraction. 



The westernmost of the Mingan Islands came well into 

 view on one side, with Anticosti on the other, after 

 passing the mouth of the St. John. These islands are 

 twenty-nine in number, some of them being very small, 

 and the largest not exceeding eleven or twelve miles in 

 circumference. The most easterly is named the St. 

 Genevieve : the celebrated western isle is one of the Perro- 

 quets, near which lie the wrecks of the two noble steamers 

 before mentioned, together with many a fine schooner 

 and barque. 



The Mingan Islands are of lower Silurian hmestone, 

 dipping slightly to the south, at an inclination of about 

 sixty to eighty feet to the mile, outliers of the great 

 Silurian basin of North America, formerly connected with 

 Anticosti in one unbroken plain, resting on the Lauren- 

 tian rocks of the mainland, and marking the boundary 

 of the old Silurian seas. These islands of most ancient 

 fossiliferous rock (Birdseye to Calciferous) are generally 

 low, none of them having an elevation of more than 300 

 feet above the ocean ; but the mountainous mainland in 

 their rear rises to the height of more tlian 1,000 feet, and 

 in one instance already named, that of Mount St. John, an 

 elevation of more than 1,400 feet is attained. On these 



