The run of Waltham 1872 American Grade movements at 999,9xx contains examples of the Charles Vander Woerd's Patent sawtooth balance. However, the bulk of these movements have either had the balance changed to a normal expansion balance or a modified balance that has the normal form with a special alloy that appears to be the same as the alloy in the sawtooth balance. This example is 999968 with the alloy form of the balance. The movement number is scratched on the bottom side of the balance arm.
The Waltham handwritten ledgers place the production of this run of watches as starting in December of 1879 and running to June of 1882. This is corroborated by the fact that the open face examples with Woerd's Patent marking are in the run of 1,427,9xx would have been made in 1881 or 1882. Unfortunately the pages listing the open face run are missing from the ledger.
Front, Front Mark, Face, Back, Back Case Mark, Cuvette, Cuvette Mark, Movement, Movement Closeup
