244 HEROES OF SCIENCE. 



intending the works on the Somersetshire Coal 

 Canal, Mr. Smith found but few opportunities of 

 making known to scientific persons, the peculiar 

 generalizations which had taken possession of his 

 mind. But in the execution of these works he 

 was putting his thoughts into practice, informing 

 the contractors what would be the nature of the 

 ground to be cut through, what parts of the canal 

 would require unusual care to be kept water-tight, 

 what was the most advantageous system of work. 

 Another singular advantage attended this engage- 

 ment. The notions which up to this time he had 

 obtained regarding the distribution of organic 

 remains were comparatively vague. He found 

 peculiar plants in the " clift " above the coal, par- 

 ticular shells in the lias and oolites, but none in 

 the red ground, and he had combined these simple 

 facts so far as to see that " each stratum had been 

 successively the bed of the sea, and contained in 

 it the mineralized monuments of the races of 

 organic beings then in existence." But it was the 

 necessity of possessing an accurate knowledge of 

 the different sorts of rock, sand, and clay, which 

 were to be cut through on the line of the canal, 

 which led him to examine minutely and scrupu- 

 lously into the distribution of the " fossils " which 

 he had been in the habit of collecting. The result 

 was a proposition which he proved to be locally 

 true, and of practical value, and which has now 

 a world-wide application, " that each stratum con- 

 tained organized fossils peculiar to itself, and might, 



