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KF5JRV > TECH 09.09.19 20:02l 26 Lines 1306 Bytes #999 (0) @ WW
BID : 12652_KF5JRV
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Subj: Thermometer History
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Sent: 190820/1143Z 12652@KF5JRV.#NWAR.AR.USA.NA BPQK6.0.18
In circa 240BC, Philo of Byzantium (c.280-220BC) made the first
thermometer-like devices. Philo published a manuscript describing an
experiment in which a tube from a hollow sphere was extended over a jug of
water operating such that if the sphere was placed in the sun, bubbles would
be released as air expanded out of the sphere; conversely, when moved into the
shade, water rose in the tube as air in the sphere contracted, as pictured
adjacent. It is said that Hero of Alexandria (c.10-70AD) may have modeled is
thermometer work on Philo and others, such as German engineer Robert Fludd
(1574-1637), had access to Philo’s manuscript.
The next documented demonstration of a thermometer was described in Hero of
Alexandria's circa 50AD Pneumatica. Documents show that Galileo read
Hero's Pneumatics in 1589.
One of the first crude thermometers was a nine-degree scale made by Greek-born
Roman physician Galen in circa 175 AD. In particular, Galen considered boiling
water to be the hottest body, ice to be the coldest, and a mixture of equal
parts ice and boiling water to be the neutral body. He then installed four
degrees above and four degrees below the neutral point, thus making a
nine-point scale
73, Scott KF5JRV
Pmail: KF5JRV @ KF5JRV.#NWAR.AR.USA.NA
Email: KF5JRV@GMAIL.com
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