We have measured the temporal history of the latitudinal and radial gradients of E>70-MeV cosmic ray particles from 1983 to 1990 using data from the Voyager 2 and Pioneer 10 spacecraft near the heliographic equatorial plane and from Pioneer 11 and Voyager 1 at average latitudes of 16¿ and 30¿, respectively. The 26-day average integral latitudinal gradient reaches a maximum of ~-2.5 %/AU in 1987 and essentially disappears when the average current sheet tilt angle exceeds the latitude of either Pioneer 11 or Voyager 1. Its magnitude shows a very strong correlation with the tilt angle of the neutral sheet. Using the data from Pioneer 11 and Voyager 1 at different latitudes, we are also able to deduce the latitude dependence of the 26-day average differential latitudinal gradient which is found to be strong function of latitude when the tilt angle approaches zero and becomes essentially independent of latitude for tilt angles >30¿. The relationship between the latitudinal and radial gradients has been used to estimate the perpendicular diffusion coefficient for >70-MeV particles. From the slope of the regression line between the instantaneous integral latitudinal and radial gradients we deduce that the perpendicular diffusion coefficient at the Earth is about 9¿1019 cm2/s or nearly 2 orders of magnitude less than the parallel diffusion coefficient. In the outer heliosphere where the wavy current sheet has large excursions from the heliographic equator such a ratio of the perpendicular to the parallel diffusion coefficient is sufficient to short circuit the neutral sheet when the tilt is >30¿--40¿, thus explaining the lack of correlation of the gradients with the current sheet tilt angle when the tilt angle becomes large. We also find excellent agreement between the observed temporal behavior of the magnitude of the latitudinal gradient and a detailed model of solar modulation which includes time dependent drifts and an outward propagating current sheet tilt Potgieter and LeRoux [1992>. ¿ American Geophysical Union 1992