Here is a great example of the bracket in use on the abandoned Boyd's Millpond line in South Carolina. This pole has stood for 103 years. Set in 1908-1909, cut on May 12th, 2013, and laid to rest on May 17th, 2013.

References & Similar construction in SC nearby:

Another line from the Van Patton Shoals hydroelectric plant used the Bow & Arrow brackets shown here: [id=326901867]. These brackets were installed around 1910 near Woodruff, SC and are still in service!

This configuration is similar to a few different lines in SC. See here for references:

1907 wishbone brackets [id=316099658]

Post by Andrew Mika regarding the bow & arrow design [id=334335433]

Boyd's Millpond Hydroelectric Plant 1909 []

Tumblin' Shoals 1912 (related) [id=366398406]

Woodruff, SC bow & arrow in service [id=326901867]