The true test of the amateur astronomer is building their own telescope. Grinding and polishing your own mirrors is a long, arduous process. Instead of lapping the blank by hand, Laurie Hall built ...

Click to open image viewer. George Willis Ritchey built this mirror grinding machine at the Yerkes Observatory in Williams Bay, Wisconsin, in the late 1890s. Under the sponsorship of George Ellery ...

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IIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more. This is the electric motor that ...

Why build a telescope? YOLO, as the kids say. Having decided that, one must decide what type of far-seer one will construct. For his 10″ reflector, [Carl Anderson] once again said “Yolo”— this time ...