History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c12.36

c12.36

At Harappa three types of furnaces have been found · (*a*) round, (*b*) cylindrical pits dug into the ground with or without brick lining, (*c*) pear-shaped pits also dug into the ground with or without brick lining. The brick-lined ones are plastered with mud mixed with sand. It appears that the firing was not uniform; varying degrees of heat were used with evidence of intense heat in some of the furnaces, provided by vitrification of the walls. Repeated mud-sand plastering gives an indication of repeated use.