X. Description of a Clinometer. 

 By THE Right Hon. Lord WEBB SEYMOUR, f.r.s. f.r.s.e. f.l.s. 



MEMBER OF THE GEOLOGICAL SOCIETY. 



[Read May 20th, 1814.] 



XN every description of stratified rocks the importance of deter- 

 mining the position of the plane of stratification, by referring it to 

 some standard, is so obvious that to insist on it would be a needless 

 intrusion upon the time and attention of this Society. The object 

 of the present paper is to submit to the Society a description of an 

 instrument contrived for the above purpose, accompanied by draw- 

 ings, and to add an explanation of the method of using it. This 

 instrument has received the name of the Clinometer. 



The Clinometer consists of two parts, the plate and the quadrant. 

 Plate 25, exhibits both lying horizontally, the quadrant in the 

 position in which it lies packed in its case. Plate 26 shews the 

 two parts put together, lying upon an inclined surface, and adjusted 

 for an observation to determine its position. In both plates every 

 part of the instrument is represented of the real size, and the 

 references in the description are made to both by the same letters. 



The plate represented by A, is circular and of brass. On 

 the under surface, near the edge, it is thickened by a ring to give 

 it greater strength. It is supported by three feet aaa^ placed at 

 equal distances just within the ring, and made of wood, with their 

 ends flat and broad, of a form somewhat oval, and having its length 



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