Methods of operating, installing, and obtaining field data with the slope indicator and the settlement torpedo are described. The slope indicator, a pendulum-activated inclinometer lowered inside a grooved extruded aluminum casing, can measure inclination to 1 min of arc. Vertical movements are detected with a settlement torpedo which measures the elevation of joints of the aluminum casing. Conclusions from field tests performed at several rockfill dams are: (1) vertical movements are 5 to 10 times as great as horizontal movements, (2) down-slope movements develop in the core parallel to the axis and are maximum at about the lower one-third point of the section, (3) there is no movement at the point of contact between a smooth rock abutment and a rockfill, (4) lateral spreading as well as down-slope movement develop in the shells of rockfills, and (5) the compressibility of a well-compacted rockfill is slightly less than that of a wellcompacted clay core, whereas a poorly compacted rockfill is considerably more compressible.