Description and Notes:
This is a rare early example of the famous round system compass set devised in 1877 by Sigmund Riefler, son of the founder of the Riefler company, Clemens Riefler. As indicated on the lower left corner of the case, the patent number is DR 2997. Stamped on the lower right corner is the maker's signature and address, C. Riefler, Nesselwang, München. This set is dated to circa 1890 or earlier as the design of the main compass, divider, and the spring drop bow are all consistent with those illustrated in the 1893 Special exhibition catalogue of the Deutsche mechanic and optic manufacturers. The integrated, one piece construction of the needle points and the body of the spring bow divider also indicates an early date. Besides, the components of the compasses of this set were not mass produced but were individually made or adjusted, as each of them bears a consistent identification number.
It is interesting to note that, instead of swing jointed at the end of the blade or at the adjustment screw commonly found in the round system sets of later period, the upper nib (top blade) of the ruling pens and the ink point of the compasses in this set are all hinged to the body, such that they can be lifted for cleaning. In addition, the handle of the ruling pens are made of ivory insted of plastic, and that of the smaller one can be unscrewed to reveal a pricker, as usually found in early ruling pens.