Dog at the Control Center of Mashell Telephone 1 Comment / Featured Photo, The Early 1900s / By dimettler Dog at Switchboard – Mashell Telephone The Christensen family was having a little fun and their dog seems a natural at the switchboard in 1914. N.P. Christensen has just purchased the Mashell Telephone Exchange in 1912. Photo courtesy of the Haynes family. Click on image to enlarge.