Thermoscope
A thermoscope is a device that shows changes in temperature. A typical design is a tube in which a liquid rises and falls as the temperature changes. The modern thermometer gradually evolved from it with the addition of a scale in the early 17th century and standardisation throughout the 17th and 18th centuries.[1][2]
Function
Devices employing both heat and pressure were common during Galileo's time, used for fountains, nursing, or bleeding in medicine.[3] The device was built from a small vase filled with water,[4] attached to a thin vertically rising pipe, with a large empty glass ball at the top. Changes in temperature of the upper ball would exert positive or negative pressure on the water below, causing it to rise or lower in the thin column.[3] The device established fixed points but does not measure specific quantity, although it can tell when something is warmer than another thing.[5]
Essentially, thermoscopes served as a justification of sorts regarding what is observed or experienced by the senses – that the device's basic agreement with the indications of the senses generates initial confidence in its reliability.[5]
Large thermoscopes placed outdoors appeared to cause perpetual motion of contained water, and these were therefore sometimes called perpetuum mobile.[3] Galileo's own work with the thermoscope led him to develop an essentially atomistic conception of heat, published in his book Il Saggiatore in 1623.[3]
History
Santorio Santorio wrote a Commentary on the Medical Art of Galen in 1612 that described the device in print.[9] Shortly afterward, in 1617 Giuseppe Biancani published the first clear diagram. The device at this time could not be used for quantitative or standardized measurement and used the temperature of air to expand or contract gas, thereby moving a column of water.[9] It was Drebbel who announced in the early 17th century one of the earliest or possibly the first prototype, which was filled with air and blocked by water containing a little aqua fortis to prevent it from freezing and being discolored.[10]
The device was improved by early German scientist
It is possible that Francesco Sagredo or Santorio may have added some kind of scales to thermoscopes, and Robert Fludd may have accomplished something similar in 1638.[11][12] In 1701 Ole Christensen Rømer effectively invented the thermometer by adding a temperature scale (see Rømer scale) to the thermoscope.[9]
See also
References
- ^ Court, Arnold (12 May 1967). "Concerning an Important Invention" (PDF). Archived from the original (PDF) on 22 August 2016.
- .
- ^ a b c d e Valleriani, Matteo (3 June 2010). Galileo Engineer. Springer Science and Business Media.
- ^ "Who invented the thermometer". www.brannan.co.uk. Retrieved 2018-02-02.
- ^ ISBN 0195171276.
- ^ "Joule_biography". Archived from the original on 1 December 2021.
- ^ ISBN 9789048186440.
- ^ Van Helden, Albert. "Galileo Project" (PDF). Rice University. Retrieved 18 June 2015.
- ^ ISBN 9780874368758.
- ISBN 8778763266.
- ^ J. E. Drinkwater (1832)Life of Galileo Galilei page 41
- ^ The Galileo Project: Santorio Santorio
- The Galileo Project, "The Thermometer"
- Benedict, Robert P., 1984. Chapter 1, "Early attempts to measure degrees of heat", in Fundamentals of Temperature, Pressure and Flow Measurement, 3rd ed, Wiley ISBN 0-471-89383-8.