This is a clock about which little is known and no examples are known to survive. The movement is described in an article in Electrical Review and Western Electrician vol 60 No. 11 p532 of 1912.

https://archive.org/details/the-electrical-review-usa-60/page/532/mode/2up?q=%22The+Dallett+electric+clock%22

It describes a Hipp toggle pendulum clock with an unusual contact system, the count wheel has a contact arm pivoted from its centre that, when the count wheel turns a final click, falls over the contact. This would produce a good clean make and break and wiping contact and would seem well-designed. The break is claimed to be non-inductive to reduce sparking. 

The clock was patented by Swift Henry Bevan and Baxter Wynne Dallett and the patent is UK patent GB191004936A of 1910, is shown here: 

https://worldwide.espacenet.com/patent/search/family/032448429/publication/GB191004936A?q=GB191004936A

The same inventors also patented aa secondary dial mechanism in 1910:

https://worldwide.espacenet.com/patent/search/family/032564437/publication/GB191029747A?q=GB191029747A

It has been suggested that the Dallett Clock Co either changed its name to or was taken over by the National Electric Time Co. but there is as yet no evidence of this. 

If anyone knows of a clock or has information, please contact us.