JF Ptak Science Books Quick Post
I came upon a short notice in the Scientific American (January 30, 1892) for Louis-J. Troncet's ingenious and very popular instant-calculator. It was a small and powerful machine (10x6cm) that Troncet had patented in 1889, and was issued in a small book-like folding case, with the accordion folding bit containing multiplication tables. It was quick and easy to use, sold for a few dollars, and became a cheap arithmetic staple for decades.
Here's a color image of the Troncet at the National Museum of American History:
[Source: http://americanhistory.si.edu/collections/search/object/nmah_690248 For another visit with the Troncet see the History of Computers site http://history-computer.com/CalculatingTools/Gadgets/Troncet.html]