The hadron calorimeter, currently used in NOMAD,
measures the energy and direction of neutral hadrons and provides a
confirmation of the energy of charged hadrons as measured by the trackers.
It is made of eleven 4.9 cm iron plates interleaved with 1 cm thick scintillator and has
an overall area of 
and a thickness of 3.1 interaction lengths.
The scintillator consists of 3.6 m long and 18.3 cm wide strips.
The 11 strips that are directly behind one another are ganged together through adiabatic
light guides, one at each end, leading to 5" phototubes.
This provides a single longitudinal sampling.
Eighteen such assemblies are stacked vertically.
The vertical coordinate of a hadron is obtained from the assembly number it is
observed in and the horizontal coordinate by the ratio of the pulse height
observed in the two phototubes at the two ends of the assembly.
The energy resolution is 
%, with E in GeV, sufficient
for the purpose of this experiment.