It would be unfair not to include directions for the home construction of a nineteen-twenties crystal set. What you needed would cost about two dollars, plus four dollars for a pair of Brandes earphones. First, shellac one oatmeal box (or the heavier cardboard cylinder available commercially); this alone would produce a sweet smell you would never forget. Around the box, carefully wind copper wire and shellac that . Now you have, your copper coil. Affix brass tracks along its length, and the slides that run along the tracks will tune in your different stations. One end of this coil is connected to the aerial; the other end goes to your earphones. And a glistening piece of galena crystal with a cat whisker (or “feeler”) probing it is hooked into the arrangement; the reasons I never understood, but I can report that if the cat whisker hit the right spot on the crystal you had a ten per cent chance of getting something, whereas it wouldn’t work at all without the crystal.