NAKRATIVE. 45 



puff or two he would pass it to the next, and when each had had his 

 turn, it was put away and they took to their oars again. 



While detained in our tent by the rain to-day, we employed 

 ourselves in manufacturing a musquito net out of some muslin we had 

 brought for the purpose. This being provided with cords, was 

 stretched at night from one tent-pole to the other, (the tents being 

 roof-shaped, with flat gables and a tent-pole at each end,) and pegged 

 down to the ground at the sides, thus forming a tent within the tent-; 

 an arrangement quite essential to a comfortable night's rest in these 

 regions. 



The point forming the breakwater of our harbor, and to which 

 the bateau was moored, presented the first example we had seen 

 of drift scratches and grooves. Some of the grooves were several 

 feet in length, the surface a curve of eighteen inches radius, and as 

 smooth and even as if cut with a gouge. These marks were almost 

 entirely confined to the inner side of the point, where some of the 

 scratches could be traced as far below the surface of the water as we 

 could distinctly see, that is, some five or six feet ; the lake side pre- 

 sented rough points of rock, occasioned, as Prof. A. explained, by the 

 decomposition of the surface on that side, from its greater exposure 

 to the wind and waves. In the afternoon, the rain having ceased, 

 we assembled to hear the Professor's remarks on the specimens of 

 various rocks collected in the neighborhood. 



" Geology," he said, " investigates the great masses of the rocks ; mineral- 

 ogy the forms and composition of their materials. Geologists are apt to neglect 

 the study of mineralogy, and thus to overlook the differences, in different 

 countries, of rocks bearing the same name. 



" If geology had been studied first in this country, the text-books of the 

 science would read very differently. For example, there is no rock in this 

 region answering the description of true granite. We have granitic rocks 

 enough, but none of an amorphic structure. All are more or less stratified. 

 At the beginning of the century, each of the two great schools in geology 

 maintained that all rocks had but one origin, disagreeing, however, as to 

 what this origin was. The reason was, each had examined only the rocks 

 in its neighborhood. About Edinburgh the rocks are trap ; Hutton, there- 

 fore, referred everything to the action of fire. Near Freiberg there is 

 nothing but sedimentary rock ; Werner, therefore, would admit no influence ^ 

 but that of water. 



