This is a very rare combination of Palmer’s two books published in 1845.  The first booklet is Palmer’s Pocket Scale Calculator in Hardbound Book with 48 pages on usage and back page with calculator.  Included is the seldom found book titled Key to Palmer’s Computing Scale for advanced calculations.  Aaron Palmer published the first book in 1845 with Calculator riveted on back cover.  The second book is identical that provided advanced calculation formulas in book and was written by John Fuller for Palmer.  Both books measure 6 x 4 inches.  Book conditions are fair with light binding wear and some age color on inside pages.  Back page calculator in book 1 is in fair condition, stiff and we do NOT want to damage it with force.  Title page shows this was Published by Aaron Palmer in 1845 (Later editions were stamped Canfield & Warren and Published by “Aaron Palmer” or Tait & Walling).  The second booklet is titled Key to Palmer’s Computing Scale published in 1845 offering advanced formulas for use in the above book.  This seldom found book 2 title page states “Improvement to Palmer’s Endless Self-Computing Scale and Key; adapting to the different professions with examples and illustrations for each profession and also colleges, academies and schools with a Time Telegraph, Making, by uniting the two, a Computing Telegraph”.  It was written by John E. Fuller of New York in 1845.  Book 2 is in Hardbound Book with 72 pages and measures 6” x 4”.  It has original owners name written inside "J Wesley Segars Book Utica June 1846".  The single book 1 above in “Antique Office Equipment” by Thomas Russo pictures and describes Palmer’s Computing Scale as it is very RARE with a value of over $ 800 and NO mention of the seldom found second book.  In our 20 years of collecting antique calculators, this is the first combination of both booklets.  For over 160+ years old, these very rare treasures will highlight any collection.  They belong in a museum or with a serious collector.