38 



ai^ imx Zxampoxtmiikl für bie ©efc^ieBe, bie in ©anb 

 uub 8e^m eingebettet finb, in machen. SebDd^ fd^eiut er 

 in feiner 2Infid;t tiwa^ fd)tt)an!enb ju feinj benn lüä^renb 

 er in ber ©teile, h)o er ben 2:ran§^crt ber ©efd&ieBe einem 

 unb bemfelben Slgenö sufc^^reibt, unb bie x6) unten anfü^« 

 ren iDiÜ/- ben Sran^^ort ber im IDilutoinm eingebetteten 

 Qefammten ©efd^iebe ton biefem SIgenö abpngig ma^t: 

 fo be3ie^t er an einer anbern, <Seite 34 fc^on angeführten 

 ©teile, tt)o er baö (Siö aU Transportmittel namhaft mad^t, 

 biefe 5lrt beö $lran§porteß boc^ n)ieber nur auf einige biefer 

 ©efc^iebe, inbem er fagt: (Sr fei geneigt sur Slnna'^me, 

 bag bie ®efc()iebe ber Oberfläd^e, gleic^ m andren i)on 

 benen, tt)e(^e im 6anb uub Sel^m eingebettet feien („like 

 „many of those buried in tlie drift-clay and sand"), 

 burc^ ^^reibeiö tran§)}ortirt njären. 



1, We have seen, that an abundance of boulders are to be 

 found both in the drift-clay and sand of Lake Supeiior. The 

 only difference between them is, that whilst those of the surface 

 are often more or less angular, those imbedded in the clay and 

 Sand are generally more rcnnded, and often scratched and stria- 

 ted — a peculiarity, which we shall afterwards attempt to ex- 

 plain. Now, as the boulders within the drift are of the same 

 kind as those of the surface, and have, like them, a northern 

 origin, (though sometimes not a great way off,) we are naturally 

 led to the inference, that they were transported by the same 

 agencies, which must, therefore, have been at work during the 

 deposition of the drift period, Moreover, this agency must have 

 ^ been as powerful at the times of the drift and clay deposites as 

 afterwards, sinee we know that many of the included boulders 

 are as massive and as heavy as thofee of the surface. It is evi- 

 dent, therefore, that no theory can be admissible, which does 

 not at the same time account satisfactorily for the transportation 

 both of the boulders of the surfaoe and of those of drift- sand 

 and clay, Report P. 1, p, 193, 



