Before electricity there were a number of alternative methods of ironing. The traditional 'sad' or 'flat' iron was heated up on the hearth or kitchen range. The box iron contained a pre-heated 'slug' of metal, or live glowing lump of charcoal. Gas heated irons connected via a rubber tube to a gas mantle. Spirit or petrol heated irons were also available but were slightly more expensive. The main problems with the early non-electric irons were that they were dirty and the temperature was often difficult to control. Much time was wasted in heating up and cooling down to achieve the required temperature.