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THE POPULAR SCIENCE MONTHLY. 



POPULAR MISCELLANY. 



The Name Silnrian in Geology. We 



have received from Prof. Dana the follow- 

 ing note in explanation of a change in geo- 

 logical nomenclature recently proposed by 

 him : 



" The names for the grander divisions 

 of the Palaeozoic series below the Devonian 

 used in most of the recently published 

 works on geology are Cambrian, Lower Silu- 

 rian, and Upper Silurian. Cambrian was 

 proposed by Sedgwick, and Silurian by 

 Murchison, and both names are derived 

 from the names of ancient tribes of Wales. 

 In 1879 Dr. Lapworth proposed to substi- 

 tute the term Ordovician. a term of like 

 origin, for the Lower Silurian, and its adop- 

 tion is under discussion. Although not see- 

 ing any need of further change, I urged, in 

 my paper before the American Geological 

 Society at Toronto, that the name Silurian, 

 if it is to be restricted, should be used for 

 the Lower Silurian rather than the Upper, 

 on the ground that it was more just to Mur- 

 chison and better for the science. I further 

 added that for a new name for the Upper 

 Silurian, rather than go again to Wales for 

 one, we should consider the claims of Bohe- 

 mia, the land where Barrande carried for- 

 ward his great work on the Silurian and 

 associated rocks, or to the region of New 

 York and Canada, made famous geologically 

 by the Palaeozoic labors of Hall, Billings, 

 and others. I stated that the French geolo- 

 gist, De Lapparent, had already used the 

 name Bohemian for the Upper Silurian ; and 

 I then remarked that the lower portion of 

 the Upper Silurian was called the Ontario 

 Division in the Reports of 1842 and 1846 of 

 the New York geologists, Profs. Mather and 

 Emmons, and that this suggested the use of 

 the name Ontarian. This would make the 

 names for the three grand divisions referred 

 to the Cambrian, Silurian, and Ontarian. 

 "James D. Dana." 



History in High and Preparatory 

 Schools. Two opposite demands, according 

 to Mrs. Mary Sheldon Barnes, have to be 

 met in teaching history in the high school ; 

 one for the generalities which are the com- 

 monplaces of every scholar, the other for 

 fresh and independent study of historic de- 



tail from historic sources. As a solution of 

 the difficulty thus raised, the author pro- 

 poses teaching the general truth through the 

 special fact, and making each pupil judge 

 the special fact for itself in its general as- 

 pects. The first step in this direction should 

 be to give the student a little collection of 

 historic data, and extracts from contempo- 

 rary sources, together with a few questions 

 within his power to answer from these ma- 

 terials. " Then let him go by himself, like 

 Agassiz's famous student with the fish, to 

 see what he can see." The prominent char- 

 acteristics of the method employed by Prof. 

 I. B. Burgess, of Newport, R. I., for teach- 

 ing classical history preparatory to college, 

 are, almost exclusive attention to the facts 

 which are essential to the comprehension of 

 Greek and Roman life and its development ; 

 the study of primitive facts, such as maps, 

 pictures of Greek and Roman works ; 

 speeches and writings of Greeks and Ro- 

 mans ; and the use of questions about these 

 facts, which require not the simple repeti- 

 tion of them, but the gathering and compari- 

 son of different fact3, and the drawing of 

 inferences from them by the pupil himself. 



An Unsettled Part of Minnesota. The 



report of the Geological and Natural His- 

 tory Survey of Minnesota for 1887 consists 

 most largely of local details, of interest 

 chiefly to the specialist. The work was pros- 

 ecuted by three parties, two of them operat- 

 ing in the region of the original Huronian and 

 the iron-bearing rocks of northern Michigan 

 and Wisconsin, and the third in the region 

 of Rainy Lake, while briefer surveys were 

 made in other regions. Prof. N. II. Win- 

 chell's examination of the original Huronian 

 leads to some important results which have 

 a direct bearing on the classification of the 

 rocks of Minnesota and of the Northwest. 

 Prof. Alexander Winchcll describes the Hu- 

 ronian region as traversed from east to west 

 by a low, interrupted swell, called the Giant's 

 Range, and by another series of still higher 

 reliefs called the Mesabi Rantje which must, 

 however, be distinguished from another Me- 

 sabi Range but without conspicuous feat- 

 ures of mountain relief. As a rule, the sur- 

 face is rugged and uncultivable. Between 

 Fall Lake and Grand Portage, and north of 

 Grand Marais, the region is "a literal wil 



