  It is shown that the location of the Fisher zeros of the Baxter-Wu model, for
two series of finite sized clusters, with spherical boundary conditions, is
extremely simple. They lie on the unit circle in the complex Sinh[2\b{eta}J3]
plane. This is the same location as the Fisher zeros of the Ising model with
nearest neighbor interactions, J2, on the square lattice have, with
Brascamp-Kunz boundary conditions. The Baxter-Wu model is an Ising model with
three site interactions, J3, on the triangle lattice. From the leading Fisher
zeros, using finite size scaling, accurate estimates of the critical exponent
1/{\nu} are obtained. Furthermore, using the imaginary parts of the leading
zeros versus the real part of the leading zeros leads to different results
similar the results of Janke and Kenna for the nearest neighbor, Ising model on
the square lattice and extending this behavior to a multi-site interaction
system.
