Esther Earl. (Redirected from Esther Day) Esther Grace Earl (August 3, 1994 â August 25, 2010) was an American author, internet vlogger, online personality and a Nerdfighter, as well as an activist in the Harry Potter Alliance.
To begin controlled cooling, allow the kiln to cool as fast as it can for the first 300Â° so the controlled portion of the firing is taking place about 300Â° lower than the cut-off temperature.
  It is held at this temperature for sufficient time for all the material to transform into Austenite or Austenite-Cementite as the case may be. It is then slowly cooled at the rate of about 20 ÂºC/hr (36 ÂºF/hr) in a furnace to about 50 ÂºC (90 ÂºF) into the Ferrite-Cementite range.