This kiln at Sandymount on the Otago Peninsula was built in 1865 by a Scotsman named McDonald. During the 19th century lime was burnt in small kilns such as this, near the limestone deposits. Limestone, which is mainly calcium carbonate (CaCO3), was burnt to drive off carbon dioxide (CO2), leaving calcium oxide (CaO) – otherwise known as burnt lime. Crushed limestone was used to improve pastures, and burnt lime was used to make a rather inferior mortar.
Te whakamahi i tēnei tūemi
Permission of Heritage New Zealand Pouhere Taonga must be obtained before any re-use of this image.