Carpenter, William Benjamin, 1813-1885, Dallinger, W. H. (William Henry), 1842-1909 · Philadelphia, Blakiston · leaf 297
p of the paraboloid being ground out intoa spherical curve of which F is the centre, the rays in emerging fromit undergo no refraction, since each falls perpendicularly upon thepart of the surface through which it passes. A stop placed at Sprevents any of the rays reflected upwards by the mirror… … Fig. 219. the least of these, G F H, be greater than the angle of aperture ofthe object-glass, none of them can enter it. The stop S is attachedto a stem of wire, which passes vertically through the paraboloidand terminates in a knob beneath, as shown in fig. 218 ; and bymeans of this it may be…
Microscopy
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