  We present Herschel observations of the Fornax cluster at 100, 160, 250, 350
and 500u with a spatial resolution of 7 - 36 arc sec (10" = 1 kpc at
d_Fornax=17.9 Mpc). We define a sample of 11 bright galaxies, selected at 500u,
directly comparable with our past work on Virgo. We find good agreement with
previous observations made by IRAS and Planck. The FIR luminosity density is
higher (factor of three) in Fornax compared to Virgo. The 100u (42.5-122.5u)
luminosity is two orders of magnitude larger in Fornax than in the local field
as measured by IRAS. Using stellar (L_{0.4-2.5}) and FIR (L_{100-500})
luminosities we estimate a mean optical depth of tau=0.4+/-0.1 - the same value
as Virgo. For 10 of the 11 galaxies (NGC1399 excepted) we fit a modified
blackbody curve (beta=2.0) to the SEDs to derive dust masses and temperatures
of 10^{6.54-8.35} M_0 and T=14.6-24.2K respectively, comparable to Virgo. The
derived stars-to-gas(atomic) and gas(atomic)-to-dust ratios vary from 1.1-67.6
and 9.8-436.5 respectively, again consistent with Virgo. Fornax is a mass
overdensity in stars and dust of about 120 compared to the local field (30 for
Virgo). Fornax and Virgo are both a factor of 6 lower over densities in
gas(atomic) than in stars and dust indicating loss of gas, but not dust and
stars, in the cluster environment. As the brightest FIR source in either Fornax
and Virgo, NGC1365 is detected by Planck. The Planck data fit the PACS/SPIRE
SED out to 1382u with no evidence of other sources of emission ('spinning
dust', free-free, synchrotron). At the opposite end of the scale NGC1399 is
detected only at 500$\mu$m with the emission probably arising from the nuclear
radio source rather than inter-stellar dust.
