▁H ydro graph ic ▁Office ▁was ▁sending ▁navig ational ▁warnings ▁to ▁ships ▁at ▁sea ▁by ▁ 1 9 0 7 . ▁ ▁Later ▁develop ments ▁included ▁the ▁placing ▁of ▁l ighth ouses ▁and ▁bu o ys ▁close ▁to ▁shore ▁to ▁act ▁as ▁marine ▁sign posts ▁ident ifying ▁ambigu ous ▁features , ▁highlight ing ▁ha z ards ▁and ▁pointing ▁to ▁safe ▁channels ▁for ▁ships ▁approaching ▁some ▁part ▁of ▁a ▁coast ▁after ▁a ▁long ▁sea ▁voyage . ▁In ▁ 1 9 1 2 ▁N ils ▁Gust af ▁Dal én ▁was ▁awarded ▁the ▁Nobel ▁Prize ▁in ▁Physics ▁for ▁his ▁in vention ▁of ▁automatic ▁val ves ▁designed ▁to ▁be ▁used ▁in ▁combination ▁with ▁gas ▁accum ul ators ▁in ▁l ighth ouses ▁▁ 1 9 2 1 ▁saw ▁the ▁installation ▁of ▁the ▁first ▁radio be acon . ▁ ▁The ▁first ▁prototype ▁ship bor ne ▁rad ar ▁system ▁was ▁installed ▁on ▁the ▁USS ▁Le ary ▁in ▁April ▁ 1 9 3 7 . ▁ ▁On ▁November ▁ 1 8 , ▁ 1 9 4 0 ▁Mr . ▁Alfred ▁L . ▁Lo om is ▁made ▁the ▁initial ▁suggestion ▁for ▁an ▁electronic ▁air ▁navigation ▁system ▁which ▁was ▁later ▁developed ▁into ▁L OR AN ▁( long ▁range ▁navigation ▁system ) ▁by ▁the ▁Rad iation ▁Labor atory ▁of ▁the ▁Massachusetts ▁Institute ▁of ▁Technology , ▁and ▁on ▁November ▁ 1 , ▁ 1 9 4 2 ▁the ▁first ▁L OR AN ▁System ▁was ▁placed ▁in ▁operation ▁with ▁four ▁stations ▁between ▁the ▁Ch es ape ake ▁Cap es ▁and ▁Nova ▁Scot ia . ▁ ▁In