Section of a Keplerian telescope

[Opera Laboratori Fiorentini]

This model of a Keplerian telescope, cut along its length, works perfectly. Looking through the telescope, one can observe a terrestrial subject, and evaluate: 1) the magnifying power of a Keplerian telescope; 2) the large visual field of this kind of instrument; 3) the upside-down aspect of the image produced.

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