Q. David Bowers
The twentieth century has seen numerous rarity scales proposed and used. Among these are the following:
• Adams and Woodin (1913): In United States Pattern, Trial and Experimental Pieces, published in 1913, Edgar H. Adams and William H. Woodin proposed a scale for rarity that employed definite quantities:
Rarity-1 = 501 or more known to exist, R-2 = 301 to 500, R-3 = 101 to 300, R-4 = 76 to 100, R-5 = 51 to 75, R-6 = 36 to 50, R-7 = 26 to 35, R-8 = 21 to 25, R-9 = 16 to 20, R-10 = 13 to 15, R-11 = 9 to 12, R-12 = 6 to 8, R-13 = 4 to 5, R-14 = 2 or 3, and R-15 = unique, just one specimen extant.
With the Adams-Woodin scale a numismatist had specific quantitative information. An R-14 coin was an object of great rarity, as just two or three were known. If a specimen was offered at auction, the collector would do well to "reach" for it, knowing that it might be years until another became available. On the other hand, a pattern coin designated as R-5, if offered in an auction, would not have compelled such urgency. Unfortunately, many of their ratings were guesswork; others-most of all in the R-10 to R-14 range-were inflated, deliberately, in a scheme aimed at their prime customer, Waldo C. Newcomer.
• Dr. William H. Sheldon (1949): In Early American Cents, published by Harper & Brothers in 1949, Dr. Sheldon gave the best exposition of rarity seen in any reference work to that point. "One of the most neglected questions in the literature on cents is that of rarity," he wrote, continuing as follows:
Competent students in the field have always been hesitant to express an opinion on the rarity of a die because they were aware of how easy it is to be mistaken. No one can ever know for certain just how many examples of a particular variety exist, since there is no way of canvassing the entire supply of cents in one lifetime. Also, there is the possibility of a new "find," in which a whole kegful of a particular variety may turn up .... Rarity will remain to some extent a matter of opinion, subject to revision in the light of further experience, and ratings on rarity should be accepted in charity for what
they are, namely, an author's best guess on the subject. ........... The Scale for Rarity which I use is a simple 8-point one .........
Dr. Sheldon's Scale for Rarity is as follows: R-1 = common, R-2 = not so common, R-3 = scarce, R-4 = very scarce (population estimated at 76-200), R-5 = rare (31-75), R-6 = very rare (13-30), R-7 = extremely rare (4-12), and R-8 = unique or nearly unique (1, 2, or 3).
The Sheldon Scale became the most accepted rarity shorthand in American numismatics. Still, it had its problems. When applied to the series of trade dollars, for example, both the 1884 and 1885 issues would be listed as R-7 in the Sheldon Scale, even though there are 10 known 1884s and just five 1885s. The only known 1870-S $3 coin, the Eliasberg Collection specimen now in the Harry Bass Foundation Collection, would be described as simply R-8 under the Sheldon Scale. However, there is a world of difference between being unique and being one of three known, and yet R-8 applies to both categories.
In a letter, Dale R. Phelan pointed out the inadequacy of the Sheldon Scale by noting that the 1913-S half dollar, the 1845 Liberty Seated dollar, and the 1921 Morgan dollar are all R-1 per the Sheldon rating; and yet perhaps 1,000 or so 1845 dollars exist, multiple thousands of 1913-S halves, and millions of 1921 dollars. (Letter to the author, April 18, 1992)
• Other rarity scales: Various authors have proposed other rarity scales. Examples include the scale from R-1 to R-11 suggested by Grover C. Criswell in his book, Confederate and Southern States Currency; Wayne Miller's R-1 to R-12 scale used in his Morgan and Peace Dollar Textbook; the R-1 to R-10 scale given by David W. Akers in A Handbook of 20th Century United States Gold Coins; and the R-1 to R-10 scale (different from the Akers scale) used by George and Melvin Fuld in U.S. Civil War Store Cards.
Several other authors have proposed modifications of the Sheldon Scale by adding intermediate adjectival-numerical designations. United States Pattern, Experimental and Trial Pieces, by Dr. J. Hewitt Judd, 1959, suggested this: R-1 = over 1,250, R-2 = 501-1,250, R-3 = 201-500, R-4 = 76-200, R-5 = 31-75, Low R-6 = 21-30, High R-6 = 13-20, Low R-7 = 7-12, High R-7 = 4-6, R-8 = 2 or 3, and Unique. Variations on this theme were later employed by Don Taxay in Scott's Comprehensive Catalogue and Encyclopedia of U.S. Coins, by Don Kagin in Private Gold Coins and Patterns of the United States, and by others.
M.H. Bolender, in his 1950 opus, The United States Early Silver Dollars from 1794 to 1803, used an eight point scale, but did not state what each step meant. Presumably, it was a copy of the Sheldon Scale; but then, Bolender called one variety Rarity-6, although he had seen only a single example.