Victor Kullberg was one of the great makers of the second half of the 19th century.
One of his more interesting treatments was the ebauche he called the "Curiosity." It employs a spanning bridge and is set up to look, at first glance, like a tourbillion.
This example was made for T. R. Russell who were fine makers in their own right. Kullberg also made watches for Frodsham and Dent among others.