Precision Laboratoy scales were first described in 1798 and became widely available around 1830. They are basically balances with delicate, sensitive mechanisms to increase precision. From the mid-1800s they were usually enclosed in glass paneled hardwood cases with sliding or hinged front or side doors for easy access and included a drawer for weights, tweezers and other accessories. Pans on precision scales are usually brass or nickel brass and can be quite small. The balance beams usually have a fixed or separate link with a small, sharp brass ridge hanging at the bottom. The wire loops that hold the pans have a separate link called an ‘agate box’, which contains a small bar of agate carved with a groove to fit delicately over the brass ridge. The ‘rider system’, which appeared around 1850, is an overhead beam equipped with wires and hooks to add minute amounts of weight for high-precision measurements. ‘Single pan balances’ introduced in 1947 speeded up weighing through a system of hand operated cams that lowered or raised weights. Microbalances, that operate with a quartz string which twists proportionally to the weight added were described in 1956, and electronic balances soon rendered mechanical chemical balances largely obsolete. There are many specialized laboratory scales designed to weigh specific objects. Some of these are in the Opticalia Museum.

Scales that are either high precision or sensitive to the slightest weight change are required for diamonds and precious metals. Portable gold and diamond scales, that dismantle to fit in small wood boxes, suitable for a coat pocket, were produced from the mid-1800s into the 20th Century. Made of brass or nickel brass, a simple balance is typical of these scales. The beam rests in a brass frame with a fixed pointer and a vertical bar for holding or hanging by cord. Alternatively the beam is positioned on a post that comes with the set. The post may screw into the top of the box. The pans are then hung by a thin cord to the ends of the beams by means of small hooks or agate boxes. Meant for travel, these scale boxes typically contained gram weights to weigh gold and carat weights to weigh diamonds. Larger desk top variety scales for diamonds and precious metals were also designed to dismantle and fit inside a mahogany or other hardwood box drawer. Precision laboratory scales, specialized for diamonds and gold, have small, sometimes tiny pans. Coin scales, in contrast, are commonly steelyard in design with grooves or notches along the beam to set the counterpoise for quick comparison of a coin with a standard. Early money scales had graduated beams made of ivory or wood that fit in a grooved flat wood box along with the counterpoise weight for easy transportation.

Floor and counter scales, too, are mostly balance beam in design, but with large pans to weigh large items or large quantities; however, the steelyard design is common in large floor scales intended for heavy products. One reason is its simple, hardy design and durability with few interconnecting parts. The steelyard scale consists of a graduated beam (usually in pounds, kilograms, ounces or grams) secured at one end – the fulcrum – with the weighing pan extended from the other end. A counterpoise weight is then slid across the beam to find equilibrium where the weight of the object is then indicated on the beam. Floor scales are commonly 3 to 4 feet tall with pans up to a foot across. Some Victorian floor scales are high ornate, usually made of wrought iron with brass pans. The English sovereign scale is a floor scale typically made of brass and nickel brass. It uses up to 500-sovereign equivalent weights to weigh coinage. Counter scales usually have short fulcrums, so sit low on the counter. Some are housed in wood or have metal skirts to hide the workings. They are commonly decorative with wood inlay or ornate metal designs. The micrometer scale by the Dodge Co. is a counter top scale that operates by torque. A large screw passes under the apparatus through a calibrated, graduated, geared wheel that turns in coordination with the screw to indicate weight when balance is achieved.

Postal scales come in many forms and operating designs, but most are simple balances and pans on a frame mounted to a wood platform. They are usually made of brass or nickel brass. The wood base invariably has recesses to accommodate round wafer weights, which are often nested or stacked, or, less commonly, rectangular weights. If metal, a small ring may be attached to the base in which the weights are stacked. Postal scales can be plain or works of art with inlay designs in the pans and ornate frames or have a creative design in the platform. Some postal scales are self-indicating. For example, the Depose counterpoise scale is fitted with a weighted pendulum that moves along a graduated arc, or alternatively the arc scale moves beside the pendulum indicator when weight is loaded. Spring loaded postal scales of various types largely superseded scales with weights by the 1950s, at least in 1st world countries, which in turn were largely replaced by electronic scales during the 1970s. Self-indicating scales are relatively inexpensive compared to electronic scales and still available.

Weights have been made in many different shapes, including those of people and animals, but more frequently they are fashioned in geometric shapes like truncated spheres, ellipsoids, cylinders (drum weights), discs, pyramids, cubes, hexagons, octagons, cupcakes, bells and rectangular wafers to mention some. Sets of round flat brass weights usually nest within one another’ rims from heaviest to lightest. Nuremberg type weights are nested metal cups in a cup shaped container that were elaborately decorated during the 17th and 18th Centuries. The outer cup has a hinged top with a fastener and the cup itself is a precisely gauged weight. They were still advertised by distributors into the twentieth century. Very large weights will likely have a handle to hold and most cylindrical and round weights have a mushroom shaped knob or ring on top to lift by hand. Weights are typically inscribed or cast in relief to indicate their mass in ounces, grams, scruples, drams, drachmas, grains, pennyweights, carats, currency, or other units of measure. Up to a point the weights available control precision and that depends on a scale’s purpose. For example, a postal scale may only need to be accurate to within half an ounce, whereas a diamond scale needs 1000 times that precision.