Nat Turner in Jerusalem **
By: David Sheward "I tire of metaphor. We are talking in circles," cries lawyer Thomas R. Gray to Nat Turner, the leader of an 1831 slave revolt, towards the end of Nathan Alan Davis's earnest but drawn-out play Nat Turner in Jerusalem, now at the New York Theatre Workshop. Gray could have been speaking for me. The dry work so repetitively examines the motives behind Turner's infamous insurrection involving a small …