Everard Gauging Rule

Selecting an arbitrary side as A, and looking at the left-side end of the side-A, the 4 sides are named as above.

Side A

Side B

Side C

Side D

D Left

Back of Slide on C

Back of Slide on D, Left

Back of Slide on D, Right

Note

When Everard of England invented his Gauging rule in 1683 it was two sided rule with two independent slides. Later it was improved to the four side model as shown in here.

There is an inscription on the well on side A "COOK MAKER TO THE EXCISE CROWN COURT SOHO LONDON", Cook must be the maker of this particular specimen.

All the four slides are in one cycle logarithmic format with two pairs. Each pair can be joined end-to-end in case of scale overflow.

The details of the scales are here.