The following excepts are from the Silent Electric Clock Company's
catalogs from 1911, 1919 and one produced for schools (date unknown).

Firstly, are three excerpts from the 1911 catalog, showing early
versions of the Clock No. 24 followed by a Clock No. 12.

Next are three excerpts from the 1919 catalog, with Fig. 61 being a Clock
No. 24 and fig. 58 being a Clock No. 12. Apologies for the poor quality.

And last is an excerpt from a catalog for schools, showing a batch of clocks
under test, manufactured for the G.P.O. This dates to somewhere between 1910
and the mid 1920's when the company was bought by (English) Magneta.

The complete SECC catalogs can be seen by clicking here.