The microscope, : its history, construction, and applications: being a familiar introduction to the use of the instrument, and the study of microsopical science, / by Jabez Hogg.

  • Hogg, Jabez, 1817-1899.
Date:
1886
Catalogue details

Licence: Public Domain Mark

Credit: The microscope, : its history, construction, and applications: being a familiar introduction to the use of the instrument, and the study of microsopical science, / by Jabez Hogg. Source: Wellcome Collection.

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    dicular to the surface it meets. Within the prism it is subjected to two reflections at b and c, which send it forth again obliquely on the line b towards the eye- piece of the secondary body, to the left-hand side of the figure; and since at its emergence its axial ray is again perpendicular to the surface of the glass, it suffers no more refraction on passing out of the prism than on entering it. By this arrangement, the image Pig. 72. received by the right eye is formed by the rays which have passed through the left half of the objec- tive; whilst the image received by the left eye is formed by the rays which have passed through the right half, and which have been subjec- tive to two reflections within the prism, passing through only two surfaces of glass. The prism is held by the ends only on the sides of a small brass drawer, so that all the four polished surfaces are accessible, and should slide in so far that its edge may just reach the central line of the objective, and be drawn back against a stop, so as to clear the aperture of the same. In this case the straight tube acts as a single microscope. The binocular constructed as we have described performs satisfactorily up to the |th inch; but for