From The Art and Popular Culture Encyclopedia
Theatrum Orbi (shown right, also known as ars memoriae) is the title of an engraving by Johann Theodor de Bry, featured on page 55  of the book Utriusque cosmi maioris scilicet et minoris metaphysica by Robert Fludd. It depicts a theatre consisting of a scaenae frons with five doors (quinque portas) and a bay window. On the bay window are inscribed the words "THEATRUM ORBI."
Excerpt of the text that accompanies the engraving:
- Theatrum appello illud, in quo omnes vocabulorum, sententiarum, particularum orationis seu subjectorum actiones tanquam in theatro publico, ubi comoediae & tragoediae aguntur, demonstrantur.
- "I call a theatre [a place in which] all actions of words, of sentences, of particulars of a speech or of subjects are shown, as in a public theatre in which comedies and tragedies are acted."