ABSTRACT
The increase of the angular aperture, which of late years has been so greatly extended throughout all the powers of the microscope, and by which so much additional light is gained for the clearer resolution of the minute details of objects. Mr. Wenham’s binocular arrangement, with double eye-pieces and prism, through which objects under low and medium powers are seen to stand out with solid stereoscopic effect, is the greatest recent invention of the modern microscope. This striking result is effected by means of a prism placed immediately over the object-glass, and which reflects one-half of the rays that proceed up the ordinary body of the microscope into another body attached at a certain inclination to it. The convenient mechanical contrivances, moreover, of the double nose-piece, the sub-stage, and the double arm to the plano-concave mirror, are managed with far greater ease and efficiency when attached to the largest microscope.
