64 
HOW TO OBSjiiii^TE. 
We have remarked that rocks are seldom found 
in 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 little 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 common error in geology to mistake 
the apparent for the real 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. 
* Higgins.— Family Library, No. 78, 
