Primitiae gnomonicae catoptricae, hoc est, Horologiographiae nauae specularis ... (1635)
Kircher, Athanasius, 1602-1680 · Auenione : Ex typographia I. Piot ... · leaf 94
THEOREMA XXI. 78 D … C A >N 0 N IIL SEctio communis horoiogij & coni, cuius bafis, •qui efl: parallelus folis , maiorem habet decli- nationem auftralem , quam fit dictum comple- mentum eleuationis poli fupra planum datum , vt in omnibus eleuationibus poli minoribus 6C. grad. & 30. min. facit conicam fedtionem , qux…
Sundials
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
![An illustration from Mathematicall magick. Or, the wonders that may be performed by mechanicall geometry in two books, concerning mechanical powers [and] motions : being one of the most easie, pleasant, useful, (and yet most neglected) part of mathematicks ... (1680)](https://img.insideoutlibrary.com/img/200/ia-b30327751-311-0.webp)
