Richter Stone Union Building Blocks Complete Set No. 6 in Original Box with Booklet flag cards associate professor

associate professor

One example

This one portrays the phases of Venus as observed between 1833 and 1836 by astronomists Wilhelm Wolff Beer (Prussian) and Johann Heinrich Mädler (German)

has holes all around the perimeter that would have been threaded with twine or yarn in order to keep the slate from banging on the surface of a school desk--thus chalkboards like this are often called "silent" chalkboards

and Binney & Smith

Richter Stone Union Building Blocks Complete Set No. 6 in Original Box with Booklet flag cards associate professorI've long been admiring sets of stone blocks like this for years, but never have I come across a complete set, in excellent condition, in the original. box with slide top lid, and with the original design booklet showing examples of many structures one might build with them, and an extra booklet (from another set) to boot! This Union Building Blocks No. 6 set was produced by Richter & Cie Rudolstadt, Germany c. 1900 and weighs in at just over 7