THE apparatus required to measure electric power is both expensive and requires special attention. The higher the accuracy aimed at the greater is the cost of the meter, and the time and labour that has to be devoted to it rapidly increases with the accuracy demanded. To encourage the use of electricity, the Electricity Commissioners have recently allowed the testing for low–load performance to be done at one tenth instead of one twentieth of full–load capacity. Another economy they have effected is to show that an appreciable extension of the life of jewels and pivots of electric meters can often be obtained by cleaning. An article on meter jewels, their examination, grading and reconditioning, giving the recommendations by the Meter Technical Committee of the Electricity Commissioners for overcoming the present difficulties of obtaining new jewels and pivots, appears in the Electrical Review of August 8.