=========================================================================== ==> This proposal is an extension of the grade 2 open time proposal JIDAVIES.DUSTYGAL =========================================================================== Our aim is to measure the spectral energy distribution of dust at several positions in spiral disks. We will be able to accurately determine the mass fraction of dust at different temperatures, the total mass of dust, the fraction of energy emitted by dust of different temperatures and the total energy output of dust. We will also see how these properties vary with position in the disk. This information will allow us to further investigate our initial findings from ISO 200 micron observations of NGC 6946 which imply that strong radial dust temperature gradients are present in disk galaxies which cannot be detected using data from the IRAS satellite. By comparing the total energy output accurately measured with LWS to that measured using IRAS HiRes and ISO (ISOPHOT) observations at 12,25,60,100 and 200 microns we will be in position to create a set of `template' spectra corresponding to a wide range of physical conditions encountered in galactic disks.These will significantly increase the accuracy of our measurements of the internal extinction in spiral galaxies with the JIDAVIES.DUSTYGAL program. The total dust mass (and therefore dust-to-gas ratio) will be measured accurately as a function of position. Current estimates of dust mass, based on IRAS data, span over an order of magnitude.