Rolling straight edge for checking irregularities in road surfaces (1967), (40 fixed wheels with measuring wheel attached to bell and to gauge marked in 1/16 inch graduations to 1/2 inch, dismantles to 3 components and handle for transport) based on design by UK Road Research Laboratory by Leonard Farnell & Co. Ltd. (serial no. 10525/141) Rolling straight edge for checking irregularities in road surfaces (1967) 1967