Alcohol thermometer to give a background for reading the scale. The range of usefulness of the thermometer is set by the boiling point of the liquid used. In the case of the ethanol-filled thermometer, the upper limit for measurement is 78 °C (172.4 °F), which makes it useful for measuring daytime, nighttime and body temperatures, although not for anything much hotter than these. Ethanol-filled thermometers are used in preference to mercury for meteorological measurements of minimum temperatures and can be used down to −70 °C (-94 °F). The physical limitation of the ability of a thermometer to measure low temperature is the
History of geophysics things as rainfall, runoff, drainage area, velocity, river cross-section measurements and discharge. Advances in the 18th century included Daniel Bernoulli's piezometer and Bernoulli's equation as well as the Pitot tube by Henri Pitot. In the 19th century, groundwater hydrology was furthered by Darcy's law, the Dupuit-Thiem well formula, and the Hagen-Poiseuille equation for flows through pipes. "Physical Geography of the Sea", the first textbook of oceanography, was written by Matthew Fontaine Maury in 1855. The thermoscope, or Galileo thermometer, was constructed by Galileo Galilei in 1607. In 1643, Evangelista Torricelli invented the mercury barometer. Blaise Pascal (in 1648) rediscovered that