Medieval technology that its potential was fully achieved. Artesian well (1126) A thin rod with a hard iron cutting edge is placed in the bore hole and repeatedly struck with a hammer, underground water pressure forces the water up the hole without pumping. Artesian wells are named after the town of Artois in France, where the first one was drilled by Carthusian monks in 1126. Central heating through underfloor channels (9th century) In the early medieval Alpine upland, a simpler central heating system where heat travelled through underfloor channels from the furnace room replaced the Roman hypocaust at some places. In Reichenau
Murder of the monks of Tibhirine Armed Islamic Group (GIA) arrived at the monastery of Tibhirine and kidnapped seven monks. Two others, Father Jean-Pierre and Father Amédée, were in separate rooms and escaped the kidnappers' notice. After the kidnappers left, the remaining monks attempted to contact the police, but found that the telephone lines had been cut. As there was a curfew in force, they had to wait until morning to drive to the police station in Médéa. On 18 April, the GIA's communiqué no. 43 announced that they would release the monks in exchange for Abdelhak Layada, a former GIA leader who had been arrested