▁the ▁first ▁to ▁make ▁system atic ▁use ▁of ▁tri ang ulation , ▁the ▁technique ▁whose ▁theory ▁was ▁described ▁by ▁Gem ma ▁F ris ius ▁in ▁his ▁ 1 5 3 3 ▁book . ▁ ▁The ▁modern ▁system atic ▁use ▁of ▁tri ang ulation ▁networks ▁st ems ▁from ▁the ▁work ▁of ▁the ▁Dutch ▁math ematic ian ▁Wille br ord ▁S nell ▁( born ▁Wille br ord ▁S nel ▁van ▁Ro yen ), ▁who ▁in ▁ 1 6 1 5 ▁survey ed ▁the ▁distance ▁from ▁Al k ma ar ▁to ▁Ber gen ▁op ▁Zo om , ▁approximately ▁ 7 0 ▁miles ▁( 1 1 0 ▁kilometres ), ▁using ▁a ▁chain ▁of ▁quadr angles ▁containing ▁ 3 3 ▁tri angles ▁in ▁all . Har wood , ▁Jer emy ▁( 2 0 0 6 ). ▁To ▁the ▁End s ▁of ▁the ▁Earth : ▁ 1 0 0 ▁Maps ▁that ▁Ch anged ▁the ▁World , ▁p . ▁ 1 0 7 ▁The ▁two ▁towns ▁were ▁separated ▁by ▁one ▁degree ▁on ▁the ▁mer id ian , ▁so ▁from ▁his ▁measurement ▁he ▁was ▁able ▁to ▁calculate ▁a ▁value ▁for ▁the ▁circum ference ▁of ▁the ▁earth ▁– ▁a ▁fe at ▁celebrated ▁in ▁the ▁title ▁of ▁his ▁book ▁Er at ost hen es ▁Bat av us ▁( The ▁Dutch ▁Er at ost hen es ), ▁published ▁in ▁ 1 6 1 7 . ▁ ▁S nell ' s ▁methods ▁were ▁taken ▁up ▁by ▁Jean ▁Pic ard ▁who ▁in ▁ 1 6 6 9 – 7 0 ▁survey ed ▁one ▁degree ▁of ▁latitude