On 22/02/2019 17:00, Rod Speed wrote:
NY wrote
Max Demian wrote

Do they still use gas marks rather than degrees Celsius in gas ovens?
I haven't seen an explanation why gas ovens use these arbitrary
numbers rather than degrees (Fahrenheit or Celsius), though I have
some ideas why it might have happened.

Yes I've never understood why gas ovens historically used arbitrary
"gas marks".

Very simple really, its just a tap. No thermostat at all.

They do have a thermostat, some of which are branded "Regulo" - hence
the expression "Regulo 3" or "Regulo Mark 3" in recipes.

The "gas marks" correspond to specific temperatures in 25 Fahrenheit
degree increments:

°F Gas Mark

225 ¼
250 ½
275 1
300 2
325 3
350 4
375 5
400 6
425 7
450 8
475 9

--
Max Demian