What remained for me but to prove, by trial, that what might be perilous to other travellers was safe to me? The “experimentum crucis” was a visit to Al-Híjaz, at once the most difficult and the most dangerous point by which a European can enter Arabia.https://en.wikisource.org/wiki/Personal_Narrative_of_a_Pilgrimage_to_Al_Madinah_and_Meccah/Volume_I

But I hold not a diagramme the only way and means of demonstrating, nor so generally necessary as you seem to urge.

Then he's down one of these adits, talking to the tommyknockers, more'n likely.

Robert Mayer is well known as one of the several codiscoverers of the principle of the conservation of energy, the formulation of which was arguably the most important single development in physics during the ...