Blog 4 Best Source
The best source I found today was one about the invention of instruments. The sourcing is extremely reliable (the author was on a team which won the Pulitzer prize). As part of my presentation I will be discussing how technology affected instrument development, and this source is exactly what I need.
For example, this source explains that after the development of metal tools for war, people may have made the discovery that hitting a sword on an empty helmet and hitting a sword on a helmet on top of a head made different noises. This may have been the inspiration behind church bells.