At the 1939 World’s Fair, Westinghouse, which had an interest in robotics even a decade before, unveiled two robot prototypes: a humanoid named Elektro and a dog named Sparko.

Elektro was able to walk, count and smoke cigarettes (which likely did not make his voice raspy, since he talked using a record player) while Sparko was able to sit up and bark.  Take that, G.E.!

elektro and sparko GE 1939 early robots
Sparko and Elektro.   The big guy was 7 feet tall and weighed 300 lbs.  No wonder science fiction was scary.   

Sparko is an English terrier, if you cannot tell, and Nicolas Nova informs us he was created by Westinghouse engineer Joseph Barnett.    Mostly Forbidden Zone has this nifty diagram of Sparko:

Sparko the robotic dog

But while a restored Elektro is now comfortably ensconced in the Mansfield Memorial Museum in Ohio, no one has seen Sparko since 1957.   Neatorama says 
The last confirmed sighting of Sparko was in California in 1957. The dogs were light-followers and legend has it that one of the three dogs was hit by a car and destroyed when it wandered out of an open door at the Westingouse lab.
So if you see a robotic dog wandering around the neighborhood, please let the folks at know about it.

If you can't visualize him from still pictures, here is some footage from the 1939 World's Fair: