These notes on Dynamo Design are not intended to super sede the more complete handbooks on the special branch of electrical engineering of which this is only a part. In the forthcoming new (seventh) edition of the Author's Dynamo Ele'ctn'c Machinery many other examples of design will be found. The present short work, intended primarily for the Author's own students, is purposely confined to continuous current generators. AS it will be used by engineers, chieﬂy in Great Britain, in her Colonies, and in the United States, the calculations and data have been expressed in inch measures. But the Author has adopted throughout the decimal subdivision of the inch; small lengths being given in mils, and small areas of cross-section in square mils; or, sometimes also, in circular mils, to suit American practice. In the section on Armature Winding Schemes special at tention is given to series-parallel windings, and to the doctrine of the equivalent ring.