A Brass and Mahogany English Portable Coin Scale by Stephen Houghton & Son, ca. 1820

Folding Guinea & Sovereign scale with a double turn counterweight, label of Stephen Houghton & Son Makers Ormskirk, Successors to A. Wilkinson.
 
In 1817 the United Kingdom introduced the gold sovereign and half-sovereign. Since the former guinea currency was left in circulation, this prompted money scale makers to adapt their designs to check weigh both types of gold coin. By 1850 the guinea had largely faded from circulation.
 
The maker’s label (left) describes the combination of flip and slide positions needed to check weigh each of the five coins described on the lid label.
 
Dimensions when folded out: 261 x 73 x 22 mm