  This paper presents the measurement of the scattering of 172 MeV/c muons in
assorted materials, including liquid hydrogen, motivated by the need to
understand ionisation cooling for muon acceleration.
  Data are compared with predictions from the Geant 4 simulation code and this
simulation is used to deconvolute detector effects. The scattering
distributions obtained are compared with the Moliere theory of multiple
scattering and, in the case of liquid hydrogen, with ELMS. With the exception
of ELMS, none of the models are found to provide a good description of the
data. The results suggest that ionisation cooling will work better than would
be predicted by Geant 4.7.0p01.
