      double precision function dlog10 (x)
c june 1977 edition.   w. fullerton, c3, los alamos scientific lab.
      double precision x, dloge, dlog
      external dlog
c
      data dloge / 0.4342944819 0325182765 1128918916 61 d0 /
c
      dlog10 = dloge * dlog(x)
c
      return
      end