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instrument extend diagonally across the corner below the level of 
the stage. They do not interfere with the substage accessories of 
the microscope, nor with any of the known types of mechanical 
stages.* 
The first model depends for its steadiness upon the steadiness 
of the microscope stand.f It is readily adjusted to any square 
Pig. 2. — Left-handed micro-manipulator to be clamped to 
microscope stage, a , needle carrier with clamping screw ; b, screw 
to clamp post of needle carrier ; c, screw for up and down movement ; 
d and e, screws for lateral movements ; /, disc guide for the horizontal 
bars ; g, stationary or rigid part of instrument, with lugs by means 
of which instrument is clamped to microscope stage. 
stage, and should prove to be a popular form. The second model 
is preferable when a microscope with a round stage is to be 
used. It is also invaluable for micro-injection work where the 
setting up of the micro-pipette is facilitated by having the micro- 
scope temporarily out of the way. Either model may be equipped 
with both a stage-clamping device and with a pillar, the advantage 
* In the case of the Bausch & Lomb and Spencer stages it may be necessary 
to replace the screw clamping the front end of the stage for one with a smaller 
head. 
t Steadiness may be assured by a brace, one end being screwed to the rigid 
vertical part of the instrument, and the other end to the foot of the microscope. 
