From Wikipedia.
A storm kettle,kelly kettle, volcano kettle or thermette is a device used for boiling water in the outdoors.
Kettle in operation with fire underneath and going up the centre chimney, water spout on the right (this one is a Kelly Kettle)
Kettle in operation with fire underneath and going up the centre chimney, water spout on the right (this one is a Kelly Kettle)
It consists of a base, in which a fire is lit (usually with wood, paper, etc.), and a double-walled main body. The centre of the main body acts as a chimney for the fire, while the water is contained in the chimney wall. A large surface area of water is thus exposed to the heat, little heat is lost directly to the atmosphere, and the centre chimney creates a upward chimney draft of heat, maximising water heating efficiency. A typical kettle can boil 2.5 pints of water in about 5 minutes. Typically, bits of paper, twigs and other small combustable material are started in the base, the kettle put on the base, and additional burnable material dropped is down the chimney as needed.
Kettles of very similar design are manufactured by the Kelly Kettle Company (Kelly Kettle) or (Volcano Kettle), the Eydon Kettle Company (Storm Kettle) and the Ghillie Kettle Company. They are all manufactured from aluminum. Two or three sizes are available, from 500 ml (~2 cups or 16 oz) to 1.5 L (~6 cups or 50 oz). The manufacturers also sell a cook sets with a little grill and pan that fits over the base. The Kelly Kettle Company also supply a Pot support which is placed in the chimney which ensures the effective use of the cook sets. The cook sets fit into the internal chimney for transport.
[edit] Thermette
The thermette, from New Zealand, is somewhat different in appearance and construction. It works on the same principle of internal upwardly narrowing chimney to create the efficient upward draught of heat, but has a different external design and use of materials. It has a cylinder shape and is flat topped (i.e., not tapered on the outside at the top), the water spout is on the flat top, it has a handle rivetted to the side for pouring instead of a chain and bail handle, and is made of copper or tin in place of aluminum.
The Thermette's history is of independent invention in 1929 by John Ashley Hart. It became a cultural icon of New Zealand's history during the Second World War. For New Zealand soldiers fighting the deserts of North Africa the Thermette became a standard piece of equipment and earned the nickname the Benghazi Boiler. The Thermette is still manufactured and is available in tin plate or copper models[citation needed]. The basic design of the Thermette is very similar to that of the storm kettle.