Keywords: William Trail.jpeg en Portrait of William Trail 1746-1831 Scottish mathematician 1780 MacTutor History of Mathematics http //turnbull mcs st-and ac uk/~history/PictDisplay/Trail html author other versions Custom license marker 2015 06 14 PD-old-100 Uploaded with UploadWizard Mathematicians from Scotland 1746 births 1831 deaths |