Original poster: "Mccauley, Daniel H by way of Terry Fritz <teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com> Also, the winding themselves are typically hollow with coolant flowing inside them. The Captain I hear the > > best ones are where they use helium to cool the windings... > > Hydrogen.. lower viscosity, cheaper, etc.