. ▁M ining ▁cam ps ▁in ▁the ▁S ina i , ▁which ▁had ▁previously ▁been ▁used ▁only ▁by ▁inter mitt ent ▁exped itions , ▁were ▁operated ▁on ▁a ▁semi - per man ent ▁basis , ▁as ▁ev iden ced ▁by ▁the ▁construction ▁of ▁houses , ▁walls , ▁and ▁even ▁local ▁c em eter ies . ▁There ▁are ▁ 2 5 ▁separate ▁references ▁to ▁min ing ▁exped itions ▁in ▁the ▁S ina i , ▁and ▁four ▁to ▁exped itions ▁in ▁W adi ▁Hamm am at , ▁one ▁of ▁which ▁had ▁over ▁two ▁thousand ▁workers . ▁A men em het ▁rein for ced ▁his ▁father ' s ▁def enses ▁in ▁N ub ia ▁and ▁continued ▁the ▁F ai y um ▁land ▁re clam ation ▁project . ▁After ▁a ▁reign ▁of ▁ 4 5 ▁years , ▁A men em het ▁III ▁was ▁succeeded ▁by ▁A men em het ▁IV , ▁whose ▁nine - year ▁reign ▁is ▁poor ly ▁att ested . ▁Clear ly ▁by ▁this ▁time , ▁d yn astic ▁power ▁had ▁begun ▁to ▁weak en , ▁for ▁which ▁several ▁explan ations ▁have ▁been ▁proposed . ▁Contempor ary ▁records ▁of ▁the ▁N ile ▁flo od ▁levels ▁indicate ▁that ▁the ▁end ▁of ▁the ▁reign ▁of ▁A men em het ▁III ▁was ▁dry , ▁and ▁c rop ▁fail ures ▁may ▁have ▁helped ▁to ▁dest abil ize ▁the ▁dynast y . ▁Further , ▁A men em het ▁III ▁had ▁an ▁in ordin ately ▁long ▁reign , ▁which ▁tends ▁to ▁create ▁succession ▁problems . ▁The ▁latter ▁argument ▁perhaps ▁explains ▁why