/usr/include/boost/units/systems/si/ is in libboost1.46-dev 1.46.1-7ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/boost/units/systems/si/absorbed_dose.hpp
/usr/include/boost/units/systems/si/acceleration.hpp
/usr/include/boost/units/systems/si/action.hpp
/usr/include/boost/units/systems/si/activity.hpp
/usr/include/boost/units/systems/si/amount.hpp
/usr/include/boost/units/systems/si/angular_acceleration.hpp
/usr/include/boost/units/systems/si/angular_momentum.hpp
/usr/include/boost/units/systems/si/angular_velocity.hpp
/usr/include/boost/units/systems/si/area.hpp
/usr/include/boost/units/systems/si/base.hpp
/usr/include/boost/units/systems/si/capacitance.hpp
/usr/include/boost/units/systems/si/catalytic_activity.hpp
/usr/include/boost/units/systems/si/codata/
/usr/include/boost/units/systems/si/codata/alpha_constants.hpp
/usr/include/boost/units/systems/si/codata/atomic-nuclear_constants.hpp
/usr/include/boost/units/systems/si/codata/deuteron_constants.hpp
/usr/include/boost/units/systems/si/codata/electromagnetic_constants.hpp
/usr/include/boost/units/systems/si/codata/electron_constants.hpp
/usr/include/boost/units/systems/si/codata/helion_constants.hpp
/usr/include/boost/units/systems/si/codata/muon_constants.hpp
/usr/include/boost/units/systems/si/codata/neutron_constants.hpp
/usr/include/boost/units/systems/si/codata/physico-chemical_constants.hpp
/usr/include/boost/units/systems/si/codata/proton_constants.hpp
/usr/include/boost/units/systems/si/codata/tau_constants.hpp
/usr/include/boost/units/systems/si/codata/triton_constants.hpp
/usr/include/boost/units/systems/si/codata/typedefs.hpp
/usr/include/boost/units/systems/si/codata/universal_constants.hpp
/usr/include/boost/units/systems/si/codata_constants.hpp
/usr/include/boost/units/systems/si/conductance.hpp
/usr/include/boost/units/systems/si/conductivity.hpp
/usr/include/boost/units/systems/si/current.hpp
/usr/include/boost/units/systems/si/dimensionless.hpp
/usr/include/boost/units/systems/si/dose_equivalent.hpp
/usr/include/boost/units/systems/si/dynamic_viscosity.hpp
/usr/include/boost/units/systems/si/electric_charge.hpp
/usr/include/boost/units/systems/si/electric_potential.hpp
/usr/include/boost/units/systems/si/energy.hpp
/usr/include/boost/units/systems/si/force.hpp
/usr/include/boost/units/systems/si/frequency.hpp
/usr/include/boost/units/systems/si/illuminance.hpp
/usr/include/boost/units/systems/si/impedance.hpp
/usr/include/boost/units/systems/si/inductance.hpp
/usr/include/boost/units/systems/si/io.hpp
/usr/include/boost/units/systems/si/kinematic_viscosity.hpp
/usr/include/boost/units/systems/si/length.hpp
/usr/include/boost/units/systems/si/luminous_flux.hpp
/usr/include/boost/units/systems/si/luminous_intensity.hpp
/usr/include/boost/units/systems/si/magnetic_field_intensity.hpp
/usr/include/boost/units/systems/si/magnetic_flux.hpp
/usr/include/boost/units/systems/si/magnetic_flux_density.hpp
/usr/include/boost/units/systems/si/mass.hpp
/usr/include/boost/units/systems/si/mass_density.hpp
/usr/include/boost/units/systems/si/moment_of_inertia.hpp
/usr/include/boost/units/systems/si/momentum.hpp
/usr/include/boost/units/systems/si/permeability.hpp
/usr/include/boost/units/systems/si/permittivity.hpp
/usr/include/boost/units/systems/si/plane_angle.hpp
/usr/include/boost/units/systems/si/power.hpp
/usr/include/boost/units/systems/si/prefixes.hpp
/usr/include/boost/units/systems/si/pressure.hpp
/usr/include/boost/units/systems/si/reluctance.hpp
/usr/include/boost/units/systems/si/resistance.hpp
/usr/include/boost/units/systems/si/resistivity.hpp
/usr/include/boost/units/systems/si/solid_angle.hpp
/usr/include/boost/units/systems/si/surface_density.hpp
/usr/include/boost/units/systems/si/surface_tension.hpp
/usr/include/boost/units/systems/si/temperature.hpp
/usr/include/boost/units/systems/si/time.hpp
/usr/include/boost/units/systems/si/torque.hpp
/usr/include/boost/units/systems/si/velocity.hpp
/usr/include/boost/units/systems/si/volume.hpp
/usr/include/boost/units/systems/si/wavenumber.hpp