This is a pronged tool, stamped Pat Feb 11 1919, came from a farmhouse/barn ~ 100 years old in West Windsor, NJ, land being sold to be "developed". What is it? Dual prongs are ground flat on both top and bottom, and pointed; the throat-crossbar between is also sharpened on both the front and back edges. The gap behind the crossbar is ~6.5 in. to the metal handle-clasp area. Including a wooden handle, 35 in. long total. Something for tensioning heavy fence wire, perhaps?
P.S. Found it, ref. http://www.leevalley.com/US/newsletters/Gardening/1186/WhatIsIt.htm
-- it is a fancy weed-puller, designed to core and lift weed with entire root. I'm going to try it on some dandelions right now!
P.P.S. Quite useful tool; even though frequently 2 jabs are needed to find the weed root, the metalwork is strong enough to use as a pry-bar to break the root if need be. Entire root removed 20% of time, else partial root broken at 2 in. This also aerates the soil at the weed site. Note: I don't aim for a turfgrass monoculture, but yellow hawkweed, broad-leaf plantain, and eventually dandelion will push other spp. out, so I periodically knock them back, so to speak.