▁to ▁Green wich ▁where ▁he ▁continued ▁work ▁on ▁May er ' s ▁L un ar ▁T ables . ▁ ▁He ▁also ▁contributed ▁to ▁the ▁N aut ical ▁Al man ac , ▁working ▁under ▁Ne vil ▁M ask ely ne , ▁Astronom er ▁Royal . ▁ ▁On ▁ 2 7 ▁September ▁ 1 7 8 6 , ▁Mason ▁wrote ▁to ▁Benjamin ▁Franklin ▁claim ing ▁to ▁have ▁returned ▁to ▁Philadelphia ▁with ▁his ▁wife , ▁seven ▁sons , ▁and ▁one ▁daughter . ▁ ▁Mason ▁was ▁very ▁ill ▁and ▁conf ined ▁to ▁his ▁bed . ▁ ▁Mason ▁also ▁shared ▁with ▁Franklin ▁the ▁design ▁for ▁an ▁astronom ical ▁project . ▁ ▁Mason ▁provided ▁no ▁explanation ▁for ▁his ▁return ▁to ▁the ▁United ▁States , ▁and ▁nothing ▁more ▁is ▁known ▁of ▁Mason ' s ▁proposed ▁project . ▁ ▁Mason ▁died ▁on ▁ 2 5 ▁October ▁ 1 7 8 6 , ▁in ▁Philadelphia . ▁He ▁was ▁buried ▁there ▁in ▁Christ ▁Church ▁Bur ial ▁Gr ound . ▁ ▁Post hum ous ▁recognition ▁The ▁cr ater ▁Mason ▁on ▁the ▁Moon ▁is ▁named ▁after ▁him . ▁ ▁Mason ▁is ▁one ▁of ▁the ▁title ▁characters ▁of ▁Thomas ▁P yn ch on ' s ▁ 1 9 9 7 ▁novel ▁Mason ▁& ▁D ixon . ▁The ▁song ▁" S ail ing ▁to ▁Philadelphia ", ▁inspired ▁by ▁P yn ch on ' s ▁book , ▁appears ▁on ▁Mark ▁Kn opf ler ' s ▁album ▁of ▁the ▁same ▁name ; ▁on ▁the ▁original ▁version , ▁Kn opf ler ▁s ings ▁the ▁role ▁of ▁D ixon ▁and ▁James