Still there was no handy portable level until 1666, The French savant, Thevenot demonstrated that a bubble of air trapped in liquid in a closed tube would stand at the centre when the tube lay level but moved sensitively away at the slightest slope.
Kodwa yeyingekabikho into yobutyaba ephathekayo de yangu1666, unocanda womFrentshi, uThevenol wabonakalisa ukuba iqampuza lomoya eligcinwe kulwelo kwityhubu evaliweyo, luhlala embindini xa ityhubu ingqengqe mthebelele kodwa iyashukuma xa uyithobile okanye uyinyusa.