288 SPARKS FROM A GEOLOGIST'S HAMMER. 



called the " strike." But, from the outcropping edge the 

 sheet of rock descends in a direction nearly at right an- 

 gles to the strike, and disappears beneath the loose super- 

 ficial materials and the other formations. It is of first 

 importance, he pretended, to ascertain in what directions 

 the rocks "dip" in different parts of the province; for if 

 a formation dips, for instance, toward the west from 

 Oamaru, then it passes under all points situated west of 

 Oamaru, and does not underlie points to the east of 

 Oamaru. This is something of no earthly utility, but I 

 am making a record of superstitions, and will proceed. 

 If the man with a hammer desired to know the direction 

 of the dip of a formation, one would suppose the most 

 economical way would be to go and look at it. But he 

 was not content with a method so direct and so cheap. 

 He pretended that the dip was often so gentle that it 

 could not be detected by a single observation. He pre- 

 tended that it varied considerably from point to point, 

 so that the position of the formation at widely separated 

 points must be ascertained in order to know the general 

 direction and average amount of the dip. Well, suppose 

 all this was necessary, why not go to the two widely 

 separated points and see what difference of elevation they 

 have? As might be expected, the man with a hammer 

 had new objections to the direct and economical method. 

 He pretended it to be necessary to hunt up all the old 

 road and canal surveys of the province, and transcribe 

 their records of elevations, arrange them in tables, and 

 lay them down on a map of the province. This was a 

 long labor, the man with a hammer all the time under 

 pay. So he obtained the altitudes of all the principal 

 points in the province. Now he argued that if the same 



