It’s been quite some time since I posted a “Gutenberg Gem”, a book from Project Gutenberg that might deserve some special attention. Today’s example contains a bunch of nice illustrations about telescopes and their associated astronomical instruments. Very nice. Not just traditional refracting telescopes, but also instruments like spectrum comparators and filar micrometers.
The Project Gutenberg eBook of Astronomical Instruments and Accessories, by Wm. Gaertner & Co..
This is really interesting and potentially useful. The Gaertner clock mechanism is very similar to Rachel’s original configuration. There’s an effort at doing a partial restoration and a picture is worth 1000 words.
RO