Date: Wed, 22 Apr 1998 17:16:03 +0100 From: "Adrian Arnold" <acarnold@acis.co.uk> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg1365$foo@default> Subject: Re: Celsius X Fahrenheit
Most interesting - thanks, Fernando. Having looked it up now, it seems that
Fahrenheit's 0 degrees was from the temperature of ice and salt mixture. Ho
hum...
Infopedia says:
Fahrenheit's first thermometers contained a column of alcohol which
expanded and contracted directly, as originally devised by Danish
astronomer Ole Roemer in 1701. Fahrenheit substituted mercury for alcohol
because its rate of expansion, although less than that of alcohol, is more
constant. Furthermore, mercury could be used over a much wider temperature
range than alcohol.
In order to reflect the greater sensitivity of his thermometer, Fahrenheit
expanded Roemer's scale so that blood heat was 90 and an ice-salt mixture
was 0; on this scale freezing point was 30. Fahrenheit later adjusted the
scale to ignore body temperature as a fixed point so that the boiling point
of water came to 212 and freezing point was 32. This is the Fahrenheit
scale that is still in use today.
> As far as I know, the difference mentioned above exists only because
> the Celsius scale was based on FRESH water while the Farenheit on SALT
water.
> The latter freezes at lower temperatures and boils at higher temperatures
> because of all the dissolved salts it contains. Now why would anyone
choose
> salt water instead of fresh water is the mystery for me........
>
> Best wishes,
>
> Fernando Rivadavia
> Tokyo, Japan
>
> ------------------------------
>
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