The refraction of the eye : a manual for students / by Gustavus Hartridge.

  • Gustavus Hartridge
Date:
1905
Catalogue details

Licence: In copyright

Credit: The refraction of the eye : a manual for students / by Gustavus Hartridge. Source: Wellcome Collection.

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    Reflection hy a Convex Surface Parallel rays falling on such a surface are reflected as divergent^ hence never meet; but if the diverging rays thus formed are carried backwards by lineSj then an imaginary image is formed which is called negative, and at a point called the ‘principal focus (p). Foci of convex mirrors are therefore virtual; and the imagej whatever the position of the object, is always virtual, erect, and smaller than the object. Fia. 6. The radius of ti e mirror is double the principal focus. Refraction Refraction hy a Plane Surface A ray of light passing through a transparent me- dium into another of a different density is refracted, unless the ray fall perpendicular to the surface sepa- rating the two media, when it continues its course without undergoing any refraction (Fig. 6, n k).
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