Combustion Apparatus consisting of a copper cylinder (100mm x 75mm diameter), the bottom of which is in the shape of a shallow re-entrant cone which forms the top of the combustion chamber. A spiral copper heat exchanger extends upwards through the cylinder, its outlet normally being connected to a condenser using a filter pump to draw the products of combustion through the apparatus. The cylinder is housed in an aluminium outer jacket (122mm x 100mm diameter), with a drop on cover with apertures to pass the outlet of the heat exchanger, the wire stirrer and a bored and split rubber bung, also supplied to accommodate a thermometer. The outer jacket has 3 legs 37mm long which, when the calorimeter is standing on the base unit, provide the combustion chamber space and the sides of which take the form of a circular Perspex shield with removable door. Supplied without Thermometer or Condenser Unit.