. Lord Webb Seymour on a Clinometer. 391 



that of determining the position of strata. The contents of a 

 «olid contained by planes may be determined from the dimensions 

 and relative positions of these planes, and for ascertaining the 

 latter the clinometer may be used, where great accuracy is not 

 wanted. Mr. Jardine has used it in gauging a pond, of which 

 the sides were pretty regular slopes. By having the end of the 

 button of the central axis and the bottom of the milled head 

 screw so adjusted by grinding, that they may be in a plane pa- 

 rallel to that of the base of the quadrant, he has made the qua- 

 drant useful in supplying the place of a common spirit -level upon 

 ■inany occasions.* 



* Tl'.e iustiument may be had from 3Ir. Cary, OptUiaii, in the Stiaiul. 



