92 Capt. Bayfield's Notes on 



we observed it in the greatest quantity in the portion of the coast which I have last described. 

 When not seen, its existence at no great distance, was indicated by the large quantity of magnetic 

 iron-sand on the beach, and by its effects upon the instruments, used on shore in the survey of the 

 coast. The compass needles were frequently and powerfully disturbed all along the north coast 

 of the St. Lawrence, not only within the limits which I have mentioned, but from Cap Tourment 

 eastward, to the eastern extremity of the Esquimaux islands, and perhaps to the longitude of 

 60° west. I must not be understood as confirming the vulgar opinion, that the compasses of 

 vessels sailing up the St. Lawrence, are affected ; on the contrary, we observed, that the needles 

 on board the Gulnare, were visibly disturbed in one or two instances only, when the vessel 

 was not more than a mile or a mile and a half from the shore. The strongest case was off Port 

 Neuf, where the beach contains large quantities of magnetic iron sand, and we were not more 

 distant than 1^ miles, yet even there the disturbance did not exceed four or five degrees ; and at 

 double the distance it became insensible. 



From the Magpie river to Mingan, the granitic rocks are hid by the alluvion 

 and the superincumbent soft strata. They pierce, however, through the sand 

 at the entrance of the Mingan river ; and afterwards appear frequently at the 

 margin of the sea, within the Mingan and Esquimaux islands, affording op- 

 portunities, occasionally, of observing their junction with the limestone of 

 which those islands are formed. 



6. The Mingan and Esquimaux islands, 29 in number, are situated just to 

 the northward of the 50° of latitude, and between the 64|° and 63|° west lon- 

 gitude, or nearly so. They range parallel to the coast from the Perroquets 

 at the west, to St. Genevieve at the east end of the chain, a distance of about 

 forty-three nautical miles. Their northern points are no where more than 

 three and a half miles from the mainland, and are generally close to it ; while 

 their southern or outer points, do not extend further off the main shore than 

 six and a half or seven miles. The most extensive island is called Large 

 Island, being about ten miles in circumference, and Esquimaux island is not 

 much smaller. The general character of the group is low, the highest points 

 not exceeding perhaps 300 feet above the sea. On the north, east, and west 

 sides, are bold and frequently steep cliffs ; but on the south side the outline 

 is low and shelving. In these and other respects, the Mingan and Esquimaux 

 islands resemble the opposite island of Anticosti, from which, at the nearest 

 point, they are distant about 14|^ miles. 



Both the groups are entirely calcareous, and the strata dip only a few 

 degrees to the southward, or a little to the westward of south. The limestone 

 varies much in different parts even of the same island, being sometimes com- 

 pact, or earthy, or shaly, at others imperfectly crystalline, and occasionally it 

 passes into a calcareous sandstone, in which grains of the minerals compo- 

 sing primitive rocks and fragments of shells, are agglutinated by a calcareous 

 cement. 



