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 refracting telescope (from ""Smith's Illustrated Astronomy"" 1848).]]
The 1845 Merz und Mahler 11 inch refractor – Housed in the ""Mitchel Building"". May be the oldest continually used telescope in the world. It is currently used for public education programs.
The 1904 Alvan Clark & Sons 16 inch refractor – Housed in the ""Herget Building"". Used in public education programs and graduate research.

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