Portrait of Leonhard Euler

In 1753 the Basel painter Jakob Emanuel Handmann was travelling through Germany, and somewhere on that trip he drew Leonhard Euler, the mathematician then working at Frederick the Great's academy in Berlin. Euler was 46. He had lost the sight of his right eye more than a decade earlier, and Frederick, who never much warmed to him, had taken to calling him his Cyclops. Handmann made the portrait in pastel, soft coloured chalk on paper, and signed and dated it in the top right corner. He drew the scholar heavy-faced and turned a little away from us. Look at the right eye: the lid hangs low and the gaze drifts slightly off.