1908 Toronto Three Ring Cancel?

I'm trying to understand why there were two completely different Toronto cancels used in what seems like only 1908.
The first picture is a normal Toronto cancel from 1907 the same style was also used in 1908,1909 &1910.
What's with this three ring cancel used for some 1908?

Cheers, Bill

The first is a machine cancel manufactured by the Internal Postal Supply Co. This is a high-speed machine typically in use at the main PO in larger cities to cancel to bulk of a city's mail.

The second is a handstamp device - note the "Station C" around the lower part of the circle.

Two different devices, 2 different locations. Toronto would have many other devices in simultaneous use during this time period.