Lecture 4

The lamplight falls on blackened walls,And streams through narrow perforations,The long beam trails o'er pasteboard scalesWith slow-decaying oscillations—Flow, current, flow, set the quick light-spot flying,Flow current, answer light-spot, flashing, quivering, dying.

O look! how queer! how thin and clear,And thinner, clearer, sharper growingThe gliding fire! with central wire,The fine degrees distinctly showing.Swing, magnet, swing, advancing and receding,Swing magnet! Answer dearest, "What's your final reading?"

O love! you fail to read the scaleCorrect to tenths of a division.To mirror heaven those eyes were given,And not for methods of precision—Break, contact, break, set the free light-spot flying;Break contact, rest thee magnet, swinging, creeping, dying.