  The FIRBACK (Far InfraRed BACKground) survey represents the deepest extensive
170 micron images obtained by the ISO satellite. The sources detected comprise
about 10% of the Cosmic IR Background (CIB) seen by COBE, and, importantly,
were observed at a wavelength near the peak of the CIB. Detailed follow-up of
these sources should help pin down the redshifts, Hubble types, and other
properties of the galaxies which constitute this background. We have used the
Submillimetre Common-User Bolometer Array (SCUBA) instrument on the James Clerk
Maxwell Telescope (JCMT) to search for sub-mm emission from a sample of 10
galaxies which are bright at 170 microns and for which we had accurate radio
positions. Statistically we detect this sample at both 450 microns (~4 sigma)
and 850 microns (~ 7 sigma); individual objects are convincingly detected in
four cases at 850 microns, and one case at 450 microns. Fits to simple spectral
energy distributions suggest a range of low to moderate redshifts, perhaps z=0
to 1.5 for this FIRBACK sub-sample.
