Lime mortar was used for millennia to adhere stone blocks together. It was the primary mortar until Portland cement was introduced in the 19th century. In this video, the Primitive Technology guy made lime mortar from the shells of rainforest snails. It's quite an involved process, and is fascinating to watch. How did people ever come up with making lime mortar in the first place? Read the rest
Researchers have found the world's oldest known tattoos -- a bull and a goat-like animal -- on a 5,200-year-old Egyptian mummy in the British Museum. From The Independent:
Along with a Copper Age European of almost identical vintage, found preserved in an Alpine glacier, the ancient Egyptian is the oldest tattooed individual ever discovered.
However, the Alpine mummy – often dubbed the Iceman – only had seemingly abstract groups of dots tattooed on him. The Egyptian, on the other hand, bears the earliest known example of tattoos in figurative art form.
Examination of the art suggests they were made with a carbon-based pigment, probably soot.