A terrella expensive ' T William Elford Leach

' T William Elford Leach (1790-1836) British naturalist was elected a Fellow of the Royal Society in 1816

'Wittington's Ghost'

and this Dock was the entrance to the English canal network from the Thames

View of Holland House

Matthew Wood

A terrella expensive ' T William Elford LeachA terrella ('little earth') is a sphere made of a magnetized substance, used to simulate the magnetic field of the earth. In the 16th century the English physician William Gilbert used a terrella made out of lodestone (a naturally occurring magnetized mineral) to demonstrate that the earth is magnetic, and to explain how mariner's compasses work. 17th century