Speedily entrusted with the management of all the ordinary business of a surveyor, Mr. Smith traversed, in continual activity, the oolitic lands of Oxfordshire and Gloucestershire, the lias clays and red marls of Warwickshire; visited (1788) the Salperton tunnel on the Thames and Severn Canal, and (1790) examined the soils and circumstances connected with a boring for coal in the New Forest, opposite the Shoe alehouse at Plaitford. All the varieties of soil, in so many surveys in different districts, were particularly noticed, and compared with the general aspect and character of the country, and the agricultural and commercial appropriations. The arrangement of the lias limestone beds in Warwickshire contrasted with the neighbouring red marls at Inkborough, the boring for coal in some dark lias clays on the road to Warwick, the absence of arenaceous beds from the limestones of Churchill—these were some of the points treasured in a mind capable of combining them at a future time. In 1793 we find him engaged in executing surveys and complete systems of levelling, for the line of a proposed canal. In the course of the operations which he performed in the summer and autumn, a speculation which had come into his mind regarding a general law affecting the strata of the district, was submitted to proof and confirmed. He had _supposed_ that the strata lying above the coal were not laid horizontally, but inclined; that they were all inclined in one direction, viz., the eastward, so as to successively terminate at the surface, and thus to “resemble, on a large scale, the ordinary appearance of superposed slices of bread and butter.” This supposition was now proved to be correct by the levelling processes executed in two parallel valleys, for in each of the levelled lines the strata of “red ground,” “lias,” and “freestone” (afterwards called “oolite”), came down in an eastern direction and sunk below the level, and yielded place to the next in succession. But at the same time it was known to Mr. Smith that the position of the strata of coal in Somersetshire was not generally conformed to that of the “red earth” “lias,” and other beds above; the same thing was proved to him by an inspection of the colliery at Bucklechurch, in Gloucestershire; he knew besides that the great faults which divide _all_ the coal strata underground, were in general found not to divide _any_ of the superincumbent rocks which formed the surface.