Have you ever wondered where the term “Breadboard” came from? Here’s an example of what breadboards were all about. In the early days of electronics, components were large and cumbersome. They didn’t have transistors or integrated circuits, only vacuum tubes. So it was common practice to build prototype circuits on a block of wood using nails or screws as circuit tie points. Tube sockets could be screwed down with standoffs, transformers and larger components were also screwed to the board. Resistors, capacitors and coils could be soldered to nailheads.This technique is still useful for some circuits. This is an example of a project I had for kids who wanted to learn electronics. They could build the circuit, following a schematic. When finished, they could take the circuit home and keep it. It did not have to be disassembled for the next user, as is the case with modern solderless breadboards. The circuit here is a simple astable multivibrator. The red and green LEDs alternate. The flashing rate is determined by the RC time constant of the resistors and capacitors.” - Link