electricity, it is not too much to expect that the Board should supply electrical energy throughout the 24 hours. However, having regard to the fact that annual charges are payable by consumers who generally require electrical energy in larger quantities than any ordinary domestic consumer for carrying on his business or establishment, the annual charges payable by him have a direct relationship with the supply of electrical energy to him at a time when he can consume the supply. The minimum guaranteed consumption itself implies that the energy is supplied when it can be consumed. No doubt, even beyond his normal working hours, such a consumer requires electrical energy for other purposes, such as security lighting etc. However, the consumption for such purposes is so small as compared to the main purpose for which electrical energy is taken, that it may be ignored in the matter of determining the liability for annual charges. So viewed, ‘constant supply’ in the context of annual charges must mean continuous supply during the normal working hours of the consumer when the supply can be consumed. This to us appears to be a fair interpretation of the agreement having regard to its purpose, commercial nature and preacticability. We are of the view that when the Board wants a guarantee from the consumer about minimum