Erector Set was a construction set that was very similar to the popular Meccano - Lego for older kids. Originally released in the early 1900s, the new Erector Sets are actually manufactured by Meccano.
Sets were varied and consisted of packs or beams that could be bolted together. There were also lots of mechanical parts like motors, pulleys and even electrical motors for making, so it was possible to make constructions like cranes and cars that actually worked. I remember getting a set for Christmas and I had to get my dad to help me work out how to put it together - it took us hours, but that's what dads are for!
An interesting fact about the Erector Sets is that they are said to be the first toy to undergo a national advertising campaign in America. To date, hundreds of different Erector Sets have been produced to keep kids (and dads) occupied at Christmas. The most memorable of these has to be set number 12, which featured the blueprints for a mysterious walking giant!