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"Ropp's Commercial Calculator: a practical arithmetic for practical purposes, containing a complete system of useful, accurate, and convenient tables, together with simple, short, and practical methods for rapid calculation", 1892

Until reliable and cheap calculators could become broadly available most calculation was carried out with the help of tables published in ready reckoners of one sort or another. The Ropp ready reckoners were widely used for this purpose in the USA right into the twentieth century.

The 1892 World's Fair Edition of Ropp's Commercial Calculator book in this collection contains 128 pages of useful mathematical facts, formulas and tables. The covers have creases, rubbing and edge and corner wear. The spine has been torn at the top and bottom. The edges of the pages are colored with red ink which is not unusual in  a late 1800's reference book. The book shows its age but is all intact with no loose pages or obvious decay.

For more on Ropp's Commercial Calculator see:

* http://www.nzeldes.com/HOC/RoppCalc_Letter.htm