Christiani Hugenii Const. F. Astroscopia Compendiaria, Tubi Optici molimine liberata

Christiaan Huygens faced a brutal optical problem: how to build telescopes long enough to see the stars clearly without the tubes collapsing under their own weight. This text reveals his ingenious solution of abandoning the tube entirely in favor of an aerial alignment system. It is a manual for turning impossible physics into everyday observation.