Thermometer 1665 Christiaan Huygens (1629–1695) suggested using the melting and boiling points of water as standards, and in 1694 Carlo Renaldini (1615–1698) proposed using them as fixed points on a universal scale. In 1701, Isaac Newton (1642–1726/27) proposed a scale of 12 degrees between the melting point of ice and body temperature. In 1714 Dutch scientist and inventor Daniel Gabriel Fahrenheit invented the first reliable thermometer, using mercury instead of alcohol and water mixtures. In 1724 he proposed a temperature scale which now (slightly adjusted) bears his name. He could do this because he manufactured thermometers, using mercury (which has a
Beckmann thermometer inverted and gently tapped so that the mercury in the reservoir lodges in the bend (B) at the end of the stem. Next, the bulb is heated until the mercury in the stem joins the mercury in the reservoir. The thermometer is then placed in a bath one or two degrees above the upper limit of temperatures to be measured. The upper end of the tube is gently tapped with the finger, and the mercury suspended in the upper part of the reservoir will be jarred down, thus separating it from the thread at the bend (B). The thermometer will