CONTRIBUTIONS TO MICRO-MINERALOGY. 



277 



Contributions to Micro-Mineralogy. By Samuel 

 HlGHLEY, F.G.S., F.C.S., &c. 



Part I. — Instruments of Micro- Mineralogical Research. 



For the preliminary inquiry as to the general features of a 

 mineral mass, I arranged an instrument that should allow of 

 its free movement in all directions, and that might be left in 

 any position during a prolonged or interrupted examination 

 by means of the ordinary hand or pocket lens ; this is deli- 

 neated in fig, 1, by which its construction will be readily 

 understood. To a firm base a ball-and-socket motion is 

 attached ; from the upper part of the ball arises a circular 

 stem on which fit three right-angled arms, capable of rotating 

 round their axis to any position, and then being clamped by a 

 broad circular stage that screws on to the axial stem ; through 

 the top of each arm a square rod passes, likewise capable of 

 being clamped at any point by little nuts ; on the end of each 

 rotates a disc, studded with three pins, which may be used 

 naked or clothed with corks, according to the nature of the 



Fig. 1. 



body under examination : a telescopic universal movement- 

 stand for the lenses completes this arrangement. The stop- 

 VOL. IV. u 



