Here it is--a collection of Forrest Mims's classic work from the original Popular Electronics magazine Using commonly available components and remarkable ingenuity, Forrest shows you how to build and experiment with circuits like these:

analog computers
color organs
digital phase-locked loops
frequency-to-voltage and voltage-to-frequency converters
interval timers
LED oscilloscopes
light wave communicators
magnetic field sensors
optoelectronics
pseudorandom number generators
tone sequencers
and much, much, more