▁then ▁direct s ▁the ▁chain man ▁to ▁make ▁the ▁chain ▁perfectly ▁straight ▁and ▁pointing ▁directly ▁at ▁the ▁r anging ▁rod . ▁A ▁pin ▁is ▁put ▁in ▁the ▁ground ▁at ▁the ▁forward ▁end ▁of ▁the ▁chain , ▁and ▁the ▁chain ▁is ▁moved ▁forward ▁so ▁that ▁its ▁h ind ▁end ▁is ▁at ▁that ▁point , ▁and ▁the ▁chain ▁is ▁extended ▁again ▁towards ▁the ▁destination ▁point . ▁This ▁process ▁is ▁called ▁r anging , ▁or ▁in ▁the ▁US , ▁chain ing ; ▁it ▁is ▁repeated ▁until ▁the ▁destination ▁rod ▁is ▁reached , ▁when ▁the ▁survey or ▁notes ▁how ▁many ▁full ▁lengths ▁( ch ains ) ▁have ▁been ▁laid , ▁and ▁he ▁can ▁then ▁directly ▁read ▁how ▁many ▁links ▁( one - h undred th ▁parts ▁of ▁the ▁chain ) ▁are ▁in ▁the ▁distance ▁being ▁measured . ▁The ▁chain ▁usually ▁ends ▁in ▁a ▁handle ▁which ▁may ▁or ▁may ▁not ▁be ▁part ▁of ▁the ▁measurement . ▁An ▁inner ▁loop ▁( visible ▁in ▁the ▁N MA H ▁photograph ) ▁is ▁the ▁correct ▁place ▁to ▁put ▁the ▁pin ▁for ▁some ▁ch ains . ▁Many ▁ch ains ▁were ▁made ▁with ▁the ▁handles ▁as ▁part ▁of ▁the ▁end ▁link ▁and ▁thus ▁were ▁included ▁in ▁the ▁measurement . ▁ ▁The ▁whole ▁process ▁is ▁repeated ▁for ▁all ▁the ▁other ▁pairs ▁of ▁points ▁required , ▁and ▁it ▁is ▁a ▁simple ▁matter ▁to ▁make ▁a ▁scale ▁diagram ▁of ▁the ▁plot ▁of ▁land . ▁The ▁process ▁is ▁surprising ly ▁accurate ▁and ▁requires ▁only ▁very ▁low ▁technology . ▁Sur ve ying ▁with ▁a ▁chain ▁is ▁simple ▁if ▁the