132 MY LIFE 



had become so serious that, for a considerable portion of the 

 canal, it had been found necessary to erect steam-engines to 

 pump up the water at every lock from the lower to the higher 

 level. Sometimes there were two, three, or more locks close 

 together, and in these cases a more powerful engine was 

 erected to pump the water the greater height. Up to this 

 time I had never seen a steam-engine, and therefore took the 

 greatest interest in examining these both at rest and at work. 

 They had been all erected by the celebrated firm of Boulton 

 and Watt, and were all of the low-pressure type then in use, 

 with large cylinders, overhead beam, and parallel motion, but 

 each one having its special features, the purport of which was 

 explained to me by my brother, and gave me my first insight 

 into some of the more important applications of the sciences 

 of mechanics and physics. 



Of course at that time nobody foresaw the rapid develop- 

 ment of railways all over the country, or imagined that they 

 could ever compete with canals in carrying heavy goods. 

 Yet within two years after the completion of the line to 

 Birmingham, the traffic of the canal had decreased to 1,000,000 

 tons, while it was 1,100,000 tons in 1837. Afterwards it 

 began slowly to rise again, and had reached 1,627,000 tons 

 in 1900, an exceedingly small increase as compared with that 

 of the railway. And this increase is wholly due to local 

 traffic between places adjacent to the canal. 



In the northern part of the parish, which extends nearly 

 to the village of Great Brickhill, were some curious dry valleys 

 with flat bottoms, and sides clothed with fir woods, a kind of 

 country I had not yet seen, and which impressed me as showing 

 some connection between the geological formation of the 

 country and its physical features, though it was many years 

 later when, by reading Lyell's " Principles of Geology," I 

 first understood why it should be so. Another interesting 

 feature of the place, which no one then saw the significance 

 of, was a large mass of hard conglomerate rock, or pudding- 

 stone, which lay in the centre of the spot where the three 

 roads met in front of the house where we lodged. It was 

 roughly about a yard in diameter and about the same height, 



