United States Post Office (Kemmerer, Wyoming)  The Kemmerer Main Post Office in Kemmerer, Wyoming was built in 1934 as part of a facilities improvement program by the United States Post Office Department. The post office in Kemmerer was nominated to the National Register of Historic Places as part of a thematic study comprising twelve Wyoming post offices built to standardized USPO plans in the early twentieth century. The Whetstone of Witte  The Whetstone of Witte is the shortened title of Robert Recorde's mathematics book published in 1557, the full title being "The whetstone of witte, whiche is the seconde parte of Arithmetike: containyng thextraction of Rootes: The "Coßike" practise, with the rule of "Equation": and the woorkes of "Surde Nombers. The book covers topics including whole numbers, the extraction of roots and irrational numbers. The work is notable for containing the first recorded use of the equals sign and also for being the first book in English to use the plus and minus signs. Recordian notation for exponentiation, however, differed from the later Cartesian notation formula_1. Recorde expressed indices and surds larger than 3 in a systematic form based on the prime factorization of the exponent: a factor of two he termed a "zenzic", and a factor of three, a "cubic". Recorde termed the larger prime numbers appearing in this factorization "sursolids", distinguishing between them by use of ordinal numbers: that is, he defined 5 as the "first sursolid", written as ʃz and 7 as the "second sursolid", written as Bʃz. He also devised symbols for these factors: a zenzic was denoted by z, and a cubic by &. For instance, he referred to "p8=p2×2×2" as zzz (the zenzizenzizenzic), and "q12=q2×2×3" as zz& (the zenzizenzicubic). Later in the book he includes a chart of exponents all the way up to "p80=p2×2×2×2×5" written as zzzzʃz. There is an error in the chart, however, writing "p69" as Sʃz, despite it not being a prime. It should be "p3×23" or &Gʃz.