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We present results for the masses and decay constants of the light mesons in quenched QCD using the standard gluon action and a tadpole--improved SW--clover fermionic action to reduce discretisation errors. The calculation has been carried out at fixed volume and three lattice spacings corresponding to $\beta=5.7$, $6.0$ and $6.2$. We make comparisons with the conventional SW--clover scheme. We use our results to extract continuum limits and to quantify the size of discretisation errors at smaller $\beta$-values., Comment: 18 pages LaTeX + 9 compressed postscript figures. Requires epsf.sty (optional), aps.sty, aps12.sty, prabib.sty and revtex.sty - {\it not} espcrc2.sty. Contribution to Lattice 95, Melbourne. Postscript version of file (in 2 column format) can be found at ftp://suna.amtp.liv.ac.uk/pub/cmi/lat95/ in the file ms.ps

Preliminary results are presented on the calculation of the relevant form factor for the radiative decay $\overline{B} \rightarrow K^* \gamma$ We find that the form factor is weakly dependent on the spectator quark mass. We compare the results obtained for a full chiral extrapolation and where this independence is assumed. Both results are found to be statistically consistent with the experimental data., Comment: 3 pages uuencoded postscript, to appear in the Proceedings of LATTICE 93 Dallas, Edinburgh Preprint 93/529

Gravitational instantons, solutions to the euclidean Einstein equations, with topology $R^3 XS^1$ arise naturally in any discussion of finite temperature quantum gravity. This Letter shows that all such instantons (irrespective of their interior behaviour) must have the same asymptotic structure as the Schwarzschild instanton. Using this, it can be shown that if the Ricci tensor of the manifold is non-negative it must be flat. One special case is when the Ricci tensor vanishes; hence one can conclude that there is no nontrivial vacuum gravitational instanton. This result has uses both in quantum and classical gravity. It places a significant restriction on the instabilities of hot flat space. It also can be used to show that any static vacuum Lorentzian Kaluza-Klein solution is flat., Comment: 10 pages