44 report — 1842. 



are ground down in the great laboratory of the lake, this oxide is liberated from 

 its siliceous connexion, and reproduced upon the shores in separate and pure beds 

 of iron sand, which are not unfrequently twelve or fourteen inches in thickness, and 

 line the shores for miles. 



Wave action is indeed more fully apparent as a mechanical power on the southern 

 shores of Superior, than at any other known point in the interior of the continent. 

 The actual process, both of degradation and resistance, in the lighter-coloured and 

 non-metallic sandstone, is nowhere better observed than along the walled and abraded 

 coast, locally known under the name of the Pictured Rocks. About twelve miles of 

 this mural coast is most completely fretted and riddled into curious architectural 

 forms by the force of equinoctial gales. " When I first saw this picturesque part of the 

 coast in 1820, a vast and high headland hung in fearful grandeur over the water, the 

 base of which was supported on pillars of the sandstone rock, forming a single arch 

 of gigantic span with several minor arches. This prominence, locally called Le Por- 

 tail, gave way the next year, throwing into the deep recesses of the lake walled masses 

 of stone, of which it will convey some estimate to add, that for every ton of rock that 

 went down with the Table rock at Niagara, one thousand tons were here engulphed. 

 Some angular points of this engulphed stratum are yet visible above the water, but 

 the latter is annually exerting its strong abrasive powers upon these rock ruins and 

 casting up the product in beach sands." 



On the Geography of the North-tvest Coast of America. By Richard King. 



In this communication the author attempted to prove, — 1. that it is not the insur- 

 mountable obstacles presented by nature that have prevented us from accomplishing 

 the grand problem of centuries — the N.W. passage. 



2. He endeavoured to point out the character of the surveyed lands contiguous to 

 parts of the Polar coast unknown. 



3. He offered proofs of the probable existence of the Isthmus of Boothia. And, 



4. Indications of the remaining portions requiring to be explored, and the modes 

 in which they may be surveyed. 



Notice of a Memoir on the Geology of the Western States of North America, 



by David Dale Owen, M.D., of Indiana. By R. I. Murchison, 



Pres. G.S. 



This memoir, with sections and characteristic fossils, having been sent to the 

 Geological Society of London, was brought to Manchester in transitu by a friend and 

 countryman of the author. Perceiving the great value of this communication, the 

 President of the Geological Society, to whom it was consigned, conceived that 

 greater justice might be done to the author by first exhibiting the fossils and sec- 

 tions to the Geological Section of the British Association, and by giving on his own 

 part a brief expose of the chief results of Dr. Dale Owen's labours, which in the 

 sequel would find their appropriate resting-place in the Transactions of the Geologi- 

 cal Society. 



The vast country in which the author had pursued his researches for a series of 

 years, in the capacity of state geologist of Indiana, embraces the states of Illinois, 

 Indiana, Ohio, Kentucky, Tennessee, and the Dubuque and Mineral Point districts of 

 Jowa and Wisconsin. 



Illustrating his views by a general section across this region, he shows that the 

 lowest rocks consist of various members of the Silurian system, the chief masses of 

 which occupying high grounds in the east and west, subside in the central districts 

 under an enormous trough of carboniferous limestone and great productive coal- 

 fields, the whole being overtopped by the equivalents of the cretaceous system of 

 Europe. Identifying many Silurian and carboniferous fossils with their types in 

 Great Britain, the author shows that the old red or Devonian rocks are less distinctly 

 developed in this than in the adjoining region to the East. At the same time he 

 points out that the Pentremite limestone occupies such an intermediate position as 



