▁refused ▁to ▁interven e , ▁the ▁city ▁government ▁handed ▁over ▁command ▁of ▁the ▁g arrison ▁to ▁K ray en hoff ▁at ▁mid night . ▁The ▁next ▁morning , ▁the ▁Amsterdam ▁Revolution ary ▁Committee ▁triumph antly ▁rode ▁to ▁city ▁hall , ▁while ▁ex ult ant ▁crow ds ▁plant ed ▁a ▁liberty ▁tree ▁on ▁Dam ▁Square . ▁ ▁In ▁ 1 7 9 6 ▁he ▁became ▁head ▁of ▁Dutch ▁fort ifications ▁and ▁moved ▁to ▁Mu iden . ▁ ▁From ▁ 1 7 9 8 ▁he ▁was ▁involved ▁in ▁organ ising ▁the ▁new ▁R ij ks water staat , ▁after ▁the ▁establishment ▁of ▁the ▁unit ary ▁state . ▁ ▁He ▁was ▁involved ▁in ▁the ▁campaign ▁against ▁the ▁Ang lo - Russ ian ▁invasion ▁of ▁Holland ▁of ▁ 1 7 9 9 ▁as ▁commander ▁of ▁the ▁Bat av ian ▁Engine ers ▁( see ▁Battle ▁of ▁Cas tr icum ) ▁and ▁ad vised ▁the ▁army ▁leadership . ▁After ▁the ▁Convention ▁of ▁Al k ma ar ▁of ▁ 1 8 ▁October ▁ 1 7 9 9 , ▁in ▁which ▁the ▁ev acu ation ▁of ▁the ▁invasion ▁troops ▁was ▁agreed , ▁K ray en hoff , ▁on ▁beh alf ▁of ▁the ▁Bat av ian ▁command ▁ins pected ▁the ▁fort ifications ▁which ▁the ▁British ▁had ▁promised ▁to ▁leave ▁int act ▁as ▁part ▁of ▁the ▁capit ulation . ▁ ▁K ray en hoff ▁was ▁mean while ▁beginning ▁his ▁life ' s ▁work ▁: ▁setting ▁up ▁a ▁system ▁of ▁tri ang ulation , ▁so ▁that ▁the ▁Netherlands ▁could ▁be ▁mapped ▁in ▁detail .