111 ACCOUTREMENT FOR Till I II I.I> 17 



should carry nothing that is not absolutely needful for 

 irpose, he may advantageously combine the pocket- 

 he one instrument in which 

 e already alluded. This convenient instrun 

 about the size of an ordinary gold wat< h. It consists of 

 n thin, round, flat metal case, shaped like that of a watch, 

 and covered cither with a common watch-glass, or still 

 i a flat disc of strong glass. Instead of figures 

 tor the hours and minutes, the white enamelled (ace 

 of this geological watch is that of a common pocket- 

 compass. Hut the interval between each of the four 



M is divided into 90. On the < 

 pivot, just underneath the needle, a small brass pendulum 

 is placed, and a straight-edge of metal is soldered on one 

 side of the out. the watch-case in such a position 



that the instrument will stand on it if need be, and the 

 pendulum will then j>oint to zero. A simple piece of 

 mechanism passing through the handle enables the 

 observer to throw the needle off the pivot, or let it down, 



as he may require. 



6. The Note-Book and Pencils. As it is impossible for 

 a field-geologist to remember the details of all the obser- 

 vations he makes on the ground, or to insert them on a 

 map, he regards a good note-book as an essential pan of 

 pparatus. From the nature of his work he has 

 frequently occasion to make rough sections, or diagrams, 

 and if possessed of the power of sketching, h. 

 abundant opportunity of aiding the progress of his 

 researches by jotting down the outlines of some cliff, 

 mountain, or landscape. Hence his note-book should 

 a mere pocket memorandum-book, fn 



