Chemical balance in a polished wood case, glass windows on all four sides. Front window is counterpoised and the side windows can be pulled back. Case has two leveling screws and one bubble level. External weights are required. Vemier is attached to permit fine readings down to 0.1 mg. For 100 g weight can discriminate to 1 part in a million.
Both arms are divided into 10 major equal parts, subdivided again into a total of 100 parts. The rigid beam carries steel knifes that turn on an agate plate. On both ends of the moving arm, light aluminium pistons are attached allowing for pneumatic damping. These pistons oppose any rapid motion of the beam. Retarding effect decreases to zero as the arm comes to rest. In order to make fine readings a 10 mg rider is used. The rider placed at the reading main divisions will have the same turning effect as weights to a total of milligrams that are placed on the pans.
EB
