128 TREVITHICK. 



tubular boiler in 1829.* On the occasion of its first trial, on the 

 21st of February, 1804, this engine drew carriages containing ten 

 tons of bar iron for a distance of nine miles, at the rate of five miles 

 an hour. The specification of the patent for Trevithick's steam- 

 carriage mentions a plan for causing the wheels, in certain cases, to 

 take a stronger hold of the ground by means of sundry rough pro- 

 jections, but it also adds that, in general, the ordinary structure or 

 .figure of the external surface of these wheels will be found to answer the 

 intended purpose, which appears to have been the case in the above- 

 mentioned engine.f After making a few experiments with his 

 engine, Trevithick forsook the locomotive for other projects of his 

 versatile genius, and this great invention was left to be perfected 

 and carried into general use by George Stephenson. 



In the year 1809 Trevithick commenced an attempt at tunnelling 

 under the Thames. It was the second time that this difficult un- 

 dertaking had been tried, Ralph Dodd having been the first of the 

 unsuccessful borers. When a large sum of money had been raised 

 by subscriptions Trevithick commenced boring at Rotherhithe, and 

 in order to save both labour and expense, kept very near to the 

 bottom of the river ; but notwithstanding the increased difficulties 

 which he had to encounter on this account, he actually carried the 

 tunnel through a distance of 1011 feet, and within 100 feet of the 

 proposed terminus. At this point an unfortunate dispute arose 

 between him and the surveyor appointed to verify his work, the 

 surveyor asserting that the tunnel had been run a foot or two on 

 one side. This reflection on his skill as an engineer excited Trevi- 

 thick's Cornish blood, and he is said to have adopted the absurd 

 expedient of making a hole in the roof of the tunnel at low water, 

 and thrusting through a series of jointed rods, which were to be 

 received by a man in a boat, and then observed from the shore. In 

 the execution of this scheme, delays ensued in fitting the rods toge- 

 ther, and at length so much water made its way through the gulley 

 formed by the opening in the roof, that retreat became necessary ; 

 Trevithick, with an inborn courage, refused to go first, but sent the 

 men before him, and his life nearly fell a sacrifice to his devotion : 

 as he made his escape on the other side, the water rose with him 

 to his neck, owing to the tunnel following the curve of the bed of 

 the river, which necessarily caused the water to congregate towards 

 one part. The work was thus ended almost at the point of its suc- 



* Sixth Dissertation, Encyclopaedia Britannica, Eighth Edition. 



j- See Practical Treatise on Railroads, &c., by Luke Hebert, London, 1837. 

 Pages 21-4. Mr. Francis Trevithick, who has spent considerable time in ascer- 

 taining the facts regarding his father's first locomotive, states that he has no 

 doubt the wheels of this engine were not in any way roughed : that he has often 

 conversed with those who made and worked the engine ; that he has their copies 

 of the original drawings ; and that in all these cases he never heard or saw any- 

 thing which indicated that the wheels were roughed. 



