A terrella expensive and this Dock was the

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

View of Holland House

Vase with gladioli and China asters

Plan of the City of London and surrounding area showing fortifications erected during the English Civil War

A terrella expensive and this Dock was theA 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