ABSTRACT
A number of instruments for automatically registering the loss of weight of a plant during transpiration have been devised, the best known, perhaps, being those described by Ganong (1905) and by Blackman and Paine (1914). In both these instruments the experimental plant is placed on one pan of a special balance, equivalent weights are added to the other pan, and the balance is kept in equilibrium by the addition of known weights at intervals as required to compensate for the loss of water during transpiration, each addition being recorded by an electrical device.
The recorder I have in present use was constructed for me by Messrs Charles Baker, 244 High Holbom, London, W.C. 1. and has given every satisfaction. Messrs Baker are in possession of full constructional details.
