64 



HOW TO O^BSERVE. 



We have remarked that rocks are seldom found 

 hi a horizontal position : had they been so, the same 

 rock must have been spread over an extensive tract 

 of country, and there would have been great diffi- 

 culty in obtaining many of those minerals which 

 are now procured at the surface with httle or no 

 trouble. This very disturbance, therefore, of the 

 crust of the earth, which at first view seems such 

 an anomaly in creation, proves conclusively the su^ 

 perintending wisdom of the Creator in the adoption 

 and arrangement of those causes best fitted to pro- 

 mote the happiness of man.* 



It is quite a conimon error in geology to mistake 

 the apparent for the re«/ inclination of the strata. 

 Figure 19 will illustrate this very clearly. It repre- 



Fig. J9. 



sents a portion of a stratified mountain, of which 

 the strata have a considerable dip to the east. If a 

 section be made in the line of bearing c d, the stra- 

 ta will appear to range from north to south without 

 any rise or dip\ and would be described, probably, 

 as being horizontal. But if another section be 

 made on the side parallel to the line of dip, as at 

 c c, the true inclination will be seen. Any section 

 made in a different direction to the line of dip will 

 cause the inclination to appear less than the true 

 one, and the line of dip will appear to vary from 

 the true dip. 



* |iiggin9.-^Fa^ily ]L.ibra;y, No. 7S 



