THE fifth annual report of the Central Electricity Board, which has just been published, is of special interest as it is the last of the reports marking the construction of the grid in Great Britain. It has only taken six years to complete instead of the estimated eight years. The cost is less than 27 million pounds and is within 2½ per cent of the original estimate of the Electricity Commissioners, a very satisfactory result considering the work has been so accelerated. In future, the main business of the Central Board will in connexion with grid trading. The main function of the grid is to see that there is an abundant supply of electrical energy at each central station so that the engineers will have more time to devote to the increase of their sales. The report shows that continuous expansion is taking place in outlying areas supplied by secondary transmission lines. The Weir Committee thought that it would be best that most of the secondary transmission should be carried out by the distributing authorities, but the Central Board found it best to regard these lines as part of the grid and so help the distributors. Successful researches have been made on methods of cheapening the cost of tapping the grid. This is a step towards supplying sparsely populated districts with electric light and power and thus encourages rural development. Instead of a tapping costing £20,000, it is hoped to reduce it to £4,000. It was feared at one time that difficulty would be obtained in getting wayleaves, but out of twenty-one thousand wayleaves obtained, less than six hundred (2.83 per cent) had to be acquired compulsorily.