# Torricelli’s mercury tube first measured atmospheric pressure 2026-08-12T10:24:28+00:00 | World & Diplomacy | Indian Opinion Desk Corroboration: 1 independent outlet In 1643, Evangelista Torricelli used a mercury-filled glass tube to measure atmospheric pressure, creating the first barometer. He inverted a 110, 120 cm tube of mercury into a basin; a column of about 76 cm remained. Torricelli argued the atmosphere's weight supported the column, describing humans living at the bottom of an 'ocean of air'. In a 1644 letter, he called it the first instrument for measuring barometric pressure. Later, Blaise Pascal's brother-in-law carried a barometer up Puy-de-Dôme in France, finding substantially lower pressure at altitude. This confirmed Torricelli's prediction that pressure decreases with height. The experiment transformed the atmosphere from an abstract concept into something measurable, and von Guericke later demonstrated its force with vacuum experiments. ## Coverage - timesofindia.indiatimes.com Tags: atmospheric pressure, barometer, history of science, Mercury, Torricelli Canonical: https://indianopinion.org/torricellis-mercury-tube-first-measured-atmospheric-pressure/ License: Summary and commentary (c) Indian Opinion, reusable with attribution. Facts belong to the linked sources. Cite: https://indianopinion.org/torricellis-mercury-tube-first-measured-atmospheric-pressure/#story-in-brief Review state: restored archive article, accurate at time of publication, not offered to search indexes.