Bourdon gauge

A quick glance at the big bourdon gauge showed this.

The Bourdon gauge for pressure readings was patented in 1849.

This was useful as previous pressure gauges were unwieldy mercury manometers and the Bourdon gauge had yet to be invented.

The Bourdon gauge or Bourdon tube is named after the Eugène Bourdon below.

Also in 1849, Bernard Schaeffer in Magdeburg, Germany patented a successful diaphragm (see below) pressure gauge, which, together with the Bourdon gauge, revolutionized pressure measurement in industry.