The sloping sides of the conical bottom can be freed from the coating of scum which forms upon them every two or three hours by two rotatory scrapers, formed of L-irons, which can be slowly turned by an attendant by means of a central shaft provided with a suitable handle.
Rotating zinc cathodes were used, with scrapers to prevent the accumulation of a layer of insoluble magnesium compounds, which would otherwise increase the electrical resistance beyond reasonable limits.
Scraping ToolsFlint scrapers are found from S.D.
Round scrapers were also made (44).
Flint scrapers were used in dressing down limestone sculpture in the IIIrd Dynasty.