▁and ▁sand ▁clock s , ▁such ▁as ▁hour glass . ▁ ▁H ourg lass es ▁were ▁still ▁in ▁use ▁by ▁the ▁Royal ▁Navy ▁of ▁Britain ▁until ▁ 1 8 3 9 ▁for ▁the ▁timing ▁of ▁watch es . ▁ ▁Cont inu ous ▁accum ulation ▁of ▁navig ational ▁data , ▁along ▁with ▁increased ▁expl oration ▁and ▁trade , ▁led ▁to ▁increased ▁production ▁of ▁volumes ▁through ▁the ▁Middle ▁A ges . ▁" Rout iers " ▁were ▁produced ▁in ▁France ▁about ▁ 1 5 0 0 ; ▁the ▁English ▁referred ▁to ▁them ▁as ▁" rut ters ." ▁In ▁ 1 5 8 4 ▁Lucas ▁W agh ena er ▁published ▁the ▁Sp ieg hel ▁der ▁Ze e va erd t ▁( The ▁Mar iner ' s ▁Mir ror ), ▁which ▁became ▁the ▁model ▁for ▁such ▁publications ▁for ▁several ▁gener ations ▁of ▁navig ators . ▁They ▁were ▁known ▁as ▁" W agg on ers " ▁by ▁most ▁sail ors . ▁ ▁In ▁ 1 5 3 7 , ▁Pedro ▁N unes ▁published ▁his ▁Tr at ado ▁da ▁S ph era . ▁In ▁this ▁book ▁he ▁included ▁two ▁original ▁treat ises ▁about ▁questions ▁of ▁navigation . ▁For ▁the ▁first ▁time ▁the ▁subject ▁was ▁approached ▁using ▁mathematical ▁tools . ▁This ▁publication ▁gave ▁rise ▁to ▁a ▁new ▁scientific ▁discipline : ▁" the oret ical ▁or ▁scientific ▁navigation ". ▁ ▁In ▁ 1 5 4 5 , ▁Pedro ▁de ▁Med ina ▁published ▁the ▁influ ential ▁Arte ▁de ▁nave gar . ▁The ▁book ▁was ▁translated ▁into ▁French , ▁Italian , ▁Dutch ▁and ▁English