
2 9 c m
40cm
actual image size: 32cm x 21cm
Description
Magnetic compases are portable and easy to use for rapid surveying where high accuracy is not required. Particularly useful in mines, the compas could be hung on hemp rope stretched along the mine gallery and the compas points used to call the direction of mineral veins.
Image Details
Image Ref.
10282299
© Science Museum / Science & Society Picture Library