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Edward Williams Barker
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Individual
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Individual
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Publication of GB189706218ApublicationCriticalpatent/GB189706218A/en
6218. Barker, E. W. March 9. central lens a, which may be formed in segments, and annular rings b, d, e, f, g built around it, also in segments. The parts, although shown as simple, are each of them compound, and are held by a suitable framework (not shown) of radial and circular bars with adjustable clamps, all interstices being filled in with opaque cement. All the elements have the same principal focus, and the straight lines bounding any section are as indicated in Fig. 1.
GB189706218D1897-03-091897-03-09Improvements in Lenses.
ExpiredGB189706218A
(en)