 However, after much effort in relocating the bacterium after exhausting the original supply (a barrel of vinegar from New Jersey), the process ended up being less cost-effective than natural rubber, and the business failed.With Edward George Boulenger of the London Zoo, he built a timer-operated electromechanical rat trap.In preparation for a diving expedition to Haiti by William Beebe and the New York Zoological Society in early 1927, in which he participated as "physicist, master electrician, and philosopher", Barr helped develop an underwater telephone allowing divers to talk to a support boat, and a brass underwater housing for a motion picture camera.