Sliding scales of chemical equivalents, has 1.243 written in on upper half of left hand side and no publisher's name on the bottom. Wollaston slide rule of chemical equivalents, England, about 1814 1814
Sliding scales of chemical equivalents, has 1814 date clearly at the bottom and alumina inscribed on the upper part of the left hand scale. Wollaston slide rule of chemical equivalents, England, 1814 1814
