▁health , ▁and ▁also ▁to ▁grat ify ▁a ▁desire ▁for ▁travel ▁and ▁scientific ▁study ▁more ▁than ▁was ▁possible ▁while ▁in ▁government ▁service . ▁ ▁In ▁these ▁later ▁years ▁his ▁time ▁and ▁attention ▁have ▁chief ly ▁been ▁occupied ▁with ▁astronom y , ▁a ▁subject ▁of ▁which ▁he ▁was ▁always ▁fond , ▁and ▁which ▁became ▁his ▁h ob by . ▁In ▁ 1 9 1 6 - 1 7 ▁he ▁built ▁an ▁observ atory , ▁" for ▁his ▁private ▁use ▁and ▁for ▁the ▁promotion ▁among ▁D ul uth ▁citizens ▁of ▁a ▁popular ▁knowledge ▁of ▁the ▁noble ▁science ▁of ▁astronom y ," ▁qu oting ▁from ▁an ▁ins cription ▁at ▁the ▁entrance . ▁Pro vision ▁has ▁been ▁made ▁for ▁the ▁future ▁maintenance ▁and ▁operation ▁of ▁the ▁observ atory ▁in ▁D ul uth , ▁by ▁the ▁General ▁Ext ension ▁Division ▁of ▁the ▁state ▁university . ▁ ▁Mr . ▁Dar ling ▁was ▁a ▁member ▁of ▁the ▁American ▁Society ▁of ▁civil ▁Engine ers ▁and ▁of ▁the ▁D ul uth ▁Section ▁of ▁that ▁society , ▁fellow ▁of ▁the ▁American ▁Association ▁for ▁the ▁Ad van cement ▁of ▁Science ; ▁member ▁of ▁the ▁American ▁Astronom ical ▁Society ; ▁member ▁of ▁the ▁Astronom ical ▁Society ▁of ▁the ▁Pacific ; ▁member ▁of ▁the ▁S ons ▁of ▁the ▁American ▁Revolution , ▁member ▁of ▁the ▁St . ▁Louis ▁County ▁Historical ▁Society ▁and ▁member ▁of ▁its ▁Board ▁of ▁Govern ors . ▁The ▁honor ary ▁degree ▁of ▁Doctor ▁of ▁Engineering ▁was ▁con ferred ▁by ▁the ▁University ▁of ▁Michigan ▁in ▁ 1 9 1 5 . ▁He ▁was ▁elected ▁to