Eaton Hodgkinson. 261 



forms of section to resist best a force of compression 

 applied in the direction of their length. 



' 7. To ascertain the resistance of wrought-iron plates to 

 a crushing force in the direction of their length. 



' 8. To determine the strength of tubes to sustain 

 impact, with reference to riveting. 



* 9. To determine, by bodies let fall upon tubes, the 

 probable effect, if any, of trains rushing rapidly upon 

 tubular bridges, to produce resilience, or springing up at 

 the ends. 



' 10. To determine the transverse strength of tubes 

 stiffened in the top with cast iron, joined with wrought 

 iron, to increase the resistance of the top to a crushing 

 force. 



' It was impossible that such assistance in the execution 

 of a novel design could 'be lightly esteemed or inadequately 

 appreciated by the great engineer. Hence, in the history 

 of these tubular bridges, where Mr. Stephenson is 

 anxious to record the merits of his assistants, he frankly 

 acknowledges his deep obligations to the mathematical 

 philosopher 'for devising- and carrying out a series of 

 experiments which terminated in establishing the laws that 

 regulate the strength of tubular structures, in a manner so 

 satisfactory that I was enabled to proceed with more con- 

 fidence than I otherwise should have done! (See vol. i. 

 p. 35, of the ' Britannia and Conway Tubular Bridges/ by 

 E. Clark, Esq.) 



( This declaration of Mr. Stephenson completely disarms 

 all future praise or detraction with respect to the part 

 which Mr. Hodgkinson took in the execution of the tubular 

 bridges. It places him before the public in his right 

 position as a most important contributor to the success of 



