The Diseases Of Electrical Machinery

PRE FACE. vii the grave-yard ; behind the Consulting electrical engineer—tell it not in Gath—lies the scrap-heap. Happily, with the co-operation of designer and constructor, of electrician and engineer, the modern dynamo has developed into a strong, healthy creature. One hears little now-a-days of many of the troubles that beset his childhood. It is true that in the seven- ties he was a puny weakling; that in the early eighties he suffered from a sudden epidemic of the disease called “ flats ” ; that owing to early mismanagement he used not only often to run away, but even to burst his binding wires. His limbs were racked by want of proper balance, and occasionally a sudden high fever caused him to shuffle ofif a mortal coil or two. But in all these things there has come, with the advent of manhood, an amazing robustness of constitution. Fifteen years ago, one could truthfully write that in those electroplating shops in London—and how few they were!—where dynamos are used, the practical men in charge of them “ almost invariably hold the firm opinion that they are not getting the current from the machine unless they can see sparks at the commutator, and they therefore so adjust the brushes that they get a good blaze.” Those good old days are gone, and with them many a species of dynamo which was unable to compete in the struggle for ex- istence. The survival of the Attest, here as every- where else, has eliminated the constitutionally unfit. Not all the skiil of the eleverest consultant can keep