Riefler, Sigmund, 1847-1912,
Das Nickelstahl-Compensationspendel, D.R.P. no. 100870 /
von S. Riefler.
- 12 pages : illustrations ; 24 cm
96199082
Pendulum--History.
Clock (general) Germany Compensation pendulum Riefler nickel Performance clock pendulum Pendulum science