50 State Quarters to form what is known as a "mule". Only sixteen of these specimens, produced on dollar planchets, escaped from the mint. A 2005 Minnesota double die quarter, as well as a 2005 Minnesota quarter with extra trees (another die error), have both triggered numismatic interest. An unusual die break on some 2005 Kansas quarters created a humpback bison. Relatively more common are Kansas quarters bearing the motto "IN GOD WE RUST." The United States produces proof coinage in circulating base metal and, since 1992, in separately sold sets with the dimes, quarters, and half-dollars in silver. For the silver issues,
Rule of thirds two thirds of water, and these together, forming about one-third of the picture, the remaining two-thirds to be for air and sky; and he applies the same rule to the crossing and breaking of lines and objects, &c. Even at this early date, there was skepticism over the universality of such a rule, at least in regards to color, for Field continues: This rule, however, does not supply a general law, but universalises a particular, the invariable observance of which would produce a uniform and monotonous practice. But, however occasionally useful, it is neither accurate nor universal, the true mean