The House Telegraph Insulator
This unusual insulator was made for use on telegraph lines supporting a telegraph designed by Royal E. House of New York. This telegraph is known as the magnetic letter printing telegraph and was patented on April 18, 1846.
The only known complete House insulator is in the archives of the Smithsonian Institution. See this link for more information on the NIA's connection with the Smithsonian!
The House insulator had a metal case with a glass insert. The conductor was clamped by the metal disk on top. These would typically be mounted on the top of the pole.
Bottom & Top: The wooden pin was sawed off and appeared to be pretty well stuck inside the glass insert which is aqua in this case. Note the square nail holding the top!
Photograph Courtesy The Smithsonian Institution See Copyright Notice