  The simultaneous invariants of 2, 3, 4 and 5 ternary quadratic forms under
the group $\SL(3, {\Bbb C})$ were given by several authors (P. Gordan, C.
Ciamberlini, H.W. Turnbull, J.A Todd), utilizing the symbolic method. Using the
Jordan algebra structure of the space of ternary quadratic forms, we give these
invariants explicitely.
