TECHNIQUES 



9-3 



lever. The micromanipulator (fig. 9-3) is pneumatically controlled. 

 It consists of two parts: (a) a set of three interconnected cylinders 

 bearing pistons and (b) a chamber housing three anaeroid foils. The 

 three pistons are so oriented with relation to each other that the 

 movement of each piston alone, or of the three simultaneously, can 

 be regulated by the use of the same lever. Each of the piston cyl- 

 inders encloses a volume of air. Air compression within the cyl- 

 inders is effected by piston movements and transmitted by means 



Fig. 9-2 The Microforge in Operation. A needle is being 

 drawn out under observation through the microscope. 



of three independent pneumatic tubes of inextensible rubber to the 

 anaeroid foils. The degree of bulge of the anaeroids can be regu- 

 lated to the desired extent by alterations of the air pressures with- 

 in the foils by piston movements. Each anaeroid foil in turn is in 

 connection with a lever, and the three levers from the three foils 

 end in a common nose-piece that bears the dissecting needle. A 



