

A. Lange & Söhne patented their power-reserve indicator in 1879, making the present piece one of the first ever produced by the company with this mechanism. They produced two different types of the power reserve indication, that seen here, and one based on Otto Lange's patent of 1940. The power reserve mechanism in the present lot is based on patent No. 9349 (see, Reinhard Meis, A. Lange & Söhne the Watchmakers of Dresden Vol II, 2012, pp. 192-194). While both use a planetary gear either between the centre-wheel and ratchet or between the ratchet and the barrel, the earlier version had the power-reserve train under the dial. Lange later installed it under the plates without increasing the height of the movement. Other examples, including No. 13274 can be seen in Meis, op.cit. 192-194, figs. 608-619.