“Being engaged soon after to survey the lands and take the levels of a canal that was proposed to be made from the collieries to Bath, I observed a variation of the strata on the same line of level, and soon found that the lias rock, which about three miles back was full three hundred feet above this line, was now thirty feet below it, and became the bed of the river, and in that direction did not appear any more at the surface. This induced me to note the inclination of the same rock, which I knew was to be found at the head of two other valleys lying each about a mile distant from, and in a parallel direction to, the one just described, and accordingly found it to dip the same to the south-east, and sink under the rivers in a similar manner.
“From this I began to consider that other strata might also have some general inclination as well as this (though I had been frequently told by the colliers that there was no regularity in the strata above ground), yet, by tracing them through the country some miles, I found the inclination of every bed to be nearly the same as [that of] the lias; and notwithstanding the partial and local dips of many quarries which varied from this rule, I was thoroughly satisfied by these observations that everything had a general tendency to the south-east, and thence concluded there could be none of these beds to the north-west, the truth of which conjecture was soon verified by a tour of observation through the northern parts of this kingdom.”
In March, 1798, Mr. Smith purchased a small but beautiful estate, in a deep valley, within three miles of Bath, almost overgrown with wild wood, hiding in its bosom a sheet of water and a small mill. Through this retired possession the canal was cut, without greatly injuring its remarkable beauty; and, under Mr. Smith’s fond and tasteful attention the scene was partly cleared, the pond expanded to a lake, the cottage became a comfortable home, in which he passed many happy and thoughtful hours. He did not, however, at any time reside long in this favourite retreat, but took up his station for about a year at the village of Mitford, near Bath, and engaged in the last duties which he performed as resident engineer to the Coal Canal.
Owing to a misunderstanding with the Company, this occupation ceased in June, 1799, and Mr. Smith felt and acknowledged that a new era in his life had arrived. He was not only at liberty, but placed under the necessity to consider the best means of making known his geological system, and of founding upon it a professional practice, which might provide the expense of travelling to verify and extend his knowledge, and fill up the outline of a geological map of England and Wales.
In these objects, which were ever closely associated in his own mind, he was successful; the most valuable portions of his discoveries soon became public property, and he quickly acquired extensive employment in the practical applications of these discoveries to mineral surveying and draining of land on a large scale. The extensive diffusion of his fame and opinions, which now began, was owing to no actual and authorized publication, but to continual discussions and explorations with several active friends, oral communications and exhibitions of maps at agricultural meetings (then frequent), and circulation of manuscript copies of tabular expositions of the series of strata at that time determined.
His views at this epoch appear by the following notice:—
“During my five years’ close confinement to practical engineering on the Coal Canal, my much-wished-for opportunity of collecting observations enough from the ranges of the different strata to make an accurate delineation of the stratification throughout England were suspended.
“I had seen enough by my tour of August, 1794, to satisfy myself of the practicability of doing it, and often wasted much time in poring over maps, in contriving how the ranging edges and planes of different strata could best be rendered intelligible: models were thought of, and one small map was cut along the edges of some of the strata with a view of defining their extent, and of showing how one stratum was successively covered by another.
“I drew in colours, on a map of the vicinity of Bath, and on ‘Day and Masters’ county survey,’ all [that had been observed] very accurately to a certain extent, which embraced an interesting but intricate variety of strata in hills around Bath; and some small maps of England were spoiled by speculating on the ranges of stratification without sufficient data. The intricacies in their marginal edges were such that I found, to mark point by point, as the facts were ascertained, was the only way in which I could safely proceed.