  The asymptotic charges of spin-1 and spin-2 fields are studied near spatial
infinity. We evaluate the charges at the critical sets where spatial infinity
meets null infinity with the aim of finding the relation between the charges at
future and past null infinity. To this end, we make use of Friedrich's
framework of the cylinder at spatial infinity to obtain asymptotic expansions
of the Maxwell and spin-2 fields near spatial infinity, which are fully
determined in terms of initial data on a Cauchy hypersurface. Expanding the
initial data in terms of spin-weighted spherical harmonics, it is shown that
only a subset of the initial data, that satisfies certain regularity
conditions, gives rise to well-defined charges at the point where future (past)
infinity meets spatial infinity. Given such initial data, the charges are shown
to be fully expressed in terms of the freely specifiable part of the data.
Moreover, it is shown that there exists a natural correspondence between the
charges defined at future and past null infinity.
