We present preliminary results of an improved measurement of the inclusive <i>b</i> quark fragmentation function in <i>Z</i><sup>0</sup> decays using a novel kinematic <i>B</i> hadron energy reconstruction technique. The measurement is performed using 350,000 hadronic <i>Z</i><sup>0</sup> events recorded in the SLD experiment at SLAC between 1997 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological <i>B</i>-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measure the <i>B</i> energy with good efficiency and resolution over the full kinematic range. We compare the measured scaled <i>B</i> hadron energy distribution with predictions of several models of <i>b</i> quark fragmentation and several functional forms of the <i>B</i> hadron energy distribution. Many of these are excluded by the data. The average scaled energy of the weakly decaying <i>B</i> hadron is measured to be <i>x<sub>B</sub></i> = 0.710 &#177; 0.003 (stat) &#177; 0.005 (syst) &#177; 0.004 (model) (preliminary).