WARSAW, POLAND—Archaeologist Krzysztof Tunia of Poland’s Institute of Archaeology and Ethnology suggests new light sources developed along with agriculture, according to a report in Science in Poland. Bonfires and wood torches were the primary source of light up until about 7,000 years ago, Tunia said, until simple pottery lamps came into use alongside the development of pottery for storage and cooking. Early lamps consisted of a wick made of plant material submerged in a flammable substance held in a shallow vessel. Many such vessels dating to the late Mesolithic and early Neolithic periods have been found in northern Poland, near the Baltic Sea, where the fat of marine animals could have been used as fuel. This could explain why similar lamps are not found in southern Poland, Tunia explained. There, charcoal found at a Neolithic flint mine is thought to have been left behind from torches used for light. Charcoal lines on the walls of the mine may have been made by rubbing the tip of the torch on the wall to create a larger flame. Lights would also have been needed to light the inside of dwellings, Tunia said, because doors and windows were limited in order to provide shelter and keep in warmth. For more go to “Off The Grid: Krakow, Poland.”