ASSAY-BALANCE, or Essay-Balance, the flat pieces of glass often placed under the scales of an assay-balance, seem, by their power of electricity, capable of attracting, and thereby making the lighter scale preponderate, where the whole matter weighed is so very small. See Essay-Balance.
The electricity of a flat surface of about three inches square has been known to hold down one scale, when there were about 200 grains weight in the other. See BALANCE.