A 4-volt induction coil, with label inscribed ~WREN'S, 4, Powis Square, W., on mahogany base stamped with maker's trademark GA, and numbered 2864, -- 12¾in.(32.4cm.) wide; a Lindermann electrometer; a Gambell Bros. post-office resistance box; and a mirror glass 'mercury' cup -- 4½in.(11.5cm.) high (4)