Hey, I've had this book sitting around for several years! It suddenly made my read real soon list:-) Ummm, that should be 120 years, not 170. FWIW: Doc Smith predicted stealth technology back in the early 40s. I think it (his use of a stealth scoutship) may date back to while radar was still highly classified. Richard Clark rclarke@gscmail.gsfc.nasa.gov