QUATERNARY FORMATIONS -THE DRIFT. 207 



position of the Range from the distribution of these lakes on the map. 

 Some of these are merely ponds of water at the bottom of typical 

 kettles, and from this they graduate by imperceptible degrees into 

 lakes of two or three miles in diameter. These are simply kettles on 

 a large scale. 



Next to the kettles themselves, the most striking feature of this 

 peculiar formation is their counterpart in the form of rounded hills 

 and hillocks, which may not inaptly be called inverted kettles. These 

 give to the surface an irregularity sometimes designated, not inap- 

 propriately, as knobby drift. The trough-like, winding depressions 

 have their counterpart in sharp, serpentine ridges. The combined 

 effect of these elevations and depressions is to give to the surface an 

 entirely distinctive character. 



These features, however, may be regarded as subordinate elements 

 of the main range, since these hillocks and depressions are variously 

 distributed over its surface. They are usually most abundant upon 

 the more abrupt face of the range, but occur in greater or less degree 

 on all sides of it, and in various situations. Not infrequently they 

 occur extensively distributed over comparatively level areas adjacent 

 to the range. Sometimes they prevail in the valleys, the adjacent hills 

 being free from them; and again they are present upon the hills, 

 but are wanting in the adjacent valleys. These facts have an import- 

 ant bearing in considering the question of their origin, which may 

 best be deferred until all the facts are presented. The range itself is 

 of composite character, being made up of a series of essentially par- 

 allel drift ridges that unite, interlock, separate, appear and disappear 

 in an irregular and intricate manner. At least four of these subordi- 

 nate ridges are often clearly discernible, and at points the number is 

 considerably increased. Associated with the main range, there are 

 occasionally sharp gravel ridges, known as "hog's-backs," rising as 

 abruptly as the nature of the material will admit, to the height of 20 

 or 30 feet, and occasionally to 60 feet, or even more. These usually 

 lie upon the flanks of the more massive ridges, and are distinguished 

 from the serpentine ridges spoken of before in no essential way except 

 in their greater size, extent and distinctness. It is usually between 

 the parallel ridges, and occupying depressions evidently caused by 

 their divergence, that most of the larger lakes associated with the 

 range are found. Ridges running across the general trend of the 



o Cj O o 



range, as well as transverse spurs extending out from it, are not un- 

 common features. The component ridges are themselves exceedingly 

 irregular in height and breath, being often much broken and inter- 

 rupted. The combined effect of all the foregoing features is to give 



