154 Craigmillar and its Environs. 



selves, stretching in a north-easterly direction towards 

 the south of Edinburgh, are joined at their northern 

 end by the Braid and Blackford hills. The Pentlands 

 attain a considerable elevation, some parts being fully 

 igoo feet above sea-level. This range of hills plays 

 a very important part in the stratification of the 

 district, forming a great anticline, with its axis ex- 

 tending along the line of the ridge, and continuing 

 northwards till it reaches the sea, — its effect on the 

 strata being to alter the bedding, and cause it to dip 

 in an easterly and westerly direction from its sides. 

 On the east side of the anticline this alteration of the 

 strata is much augmented by a great fault or dislo- 

 cation which runs along the base and parallel with the 

 Pentlands, throwing up the lower beds of the Calcifer- 

 ous Sandstone series — i.e., the red-coloured sandstones 

 that rest on the top of the Old Red Sandstone. 



The Carboniferous or coal-bearing rocks of Scotland 

 have been divided into four groups — namely : (i) The 

 Calciferous Sandstone series, which occupy the lowest 

 position ; (2) The Carboniferous Limestone series ; 

 (3) The Millstone Grit series ; and (4) The Upper 

 or Flat Coal-measures. 



