A surveying and mapping implement indicates the level differences of the ground over which it travels, in relation to the distance travelled. It comprises a carriage consisting of a swivelling front wheel, two center wheels attached to the outside of a U-shaped vertical frame, and two rear wheels connected to the U-shaped frame by means of a thill and a universal joint positioned co-extensive with the axis of the center wheels. The universal joint permits the rear wheels to move up and down and sideways, as well as to twist in relation to the center wheels. The wheel base between the center wheels and the front wheel is identical with that between the center wheels and the rear wheels, in order to facilitate calculations. Recording instruments are provided on the carriage adapted to measure the distance travelled, the different angles of inclination and of angular twist of the rear wheels in relation to the center wheels, and to transmit their output to computer means adapted to record the surface features of the ground.