  This is the second in a series of papers presenting results from the SCUBA
Local Universe Galaxy Survey. In our first paper we provided 850 micron flux
densities for 104 galaxies selected from the IRAS Bright Galaxy Sample and we
found that the 60, 100 micron (IRAS) and 850 micron (SCUBA) fluxes could be
adequately fitted by emission from dust at a single temperature. In this paper
we present 450 micron data for the galaxies. With the new data, the spectral
energy distributions of the galaxies can no longer be fitted with an isothermal
dust model - two temperature components are now required. Using our 450 micron
data and fluxes from the literature, we find that the 450/850 micron flux ratio
for the galaxies is remarkably constant and this holds from objects in which
the star formation rate is similar to our own Galaxy, to ultraluminous infrared
galaxies (ULIRGS) such as Arp 220. The only possible explanation for this is if
the dust emissivity index for all of the galaxies is ~2 and the cold dust
component has a similar temperature in all galaxies (20-21 K). The dust masses
estimated using the new temperatures are higher by a factor ~2 than those
determined previously using a single temperature. This brings the gas-to-dust
ratios of the IRAS galaxies into agreement with those of the Milky Way and
other spiral galaxies which have been intensively studied in the submm.
