 Two advantages of Stephenson's design over Davy's was that if the proportion of firedamp became too high, his lamp would be extinguished, whereas Davy's lamp could become dangerously hot.This was illustrated in the Oaks colliery at Barnsley on 20 August 1857 where both types of lamp were in use.Stephenson's design used paper to surround the flame, which cut out less of the light than Davy's, where the gauze surrounded it.