Researches on heat of combustion II: Internal lag and method of stirring in isothermally jacketed calorimeters

After a discussion of the requirements to be met by the method of stirring used in liquid calorimeters for accurate heat measurements, a description is given of a calorimeter constructed on a new principle. The development of heat occurs in a cylinder which is somewhat smaller than the calorimeter vessel. Water is circulated between the two walls, where the thermometer is placed by means of a centrally fixed centrifugal pump. In this way, the actual wall temperature of the calorimeter-vessel is measured; this is essential for the accurate calculation of the “radiation” correction. A simple method is described for determining the heat due to stirring. Finally, the required minimum duration of the main period is discussed.