CHAP. XIX. MENAI SUSPENSION BKIDGE. 417 



good engineer, he was a bad speaker." One of the 

 questions then put to Mr. Stephenson related to the 

 mode by which he proposed to haul the passenger 

 carriages over the Menai Suspension Bridge by horse 

 power ; and he was asked whether he knew the pressure 

 the bridge was capable of sustaining. His answer was, 

 that " he had not yet made any calculations ; but he 

 proposed getting data which would enable him to arrive 

 at an accurate calculation of the actual strain upon the 

 bridge during the late gale. He had, however, no hesi- 

 tation in saying that it was more than twenty times as 

 much as the strain of a train of carriages and a locomo- 

 tive engine. The only reason why he proposed to convey 

 the carriages over by horses, was in order that he might, 

 by distributing the weight, not increase the wavy mo- 

 tion. All the train would be on at once ; but distri- 

 buted. This he thought better than passing them linked 

 together, by a locomotive engine." It will thus be 

 observed that the practicability of throwing a rigid 

 railway bridge across the Straits had not yet been 

 contemplated. 



The Dublin Chamber of Commerce passed resolutions 

 in favour of Stephenson' s line, after hearing his ex- 

 planations of its essential features. The project, after 

 undergoing much discussion, was at length embodied in 

 an Act passed in 1844 ; and the work was brought to a 

 successful completion by his son, with several important 

 modifications, including the grand original feature of 

 the tubular bridges across the Menai Straits and the 

 estuary of the Conway. Excepting these great works, 

 the construction of this line presented no unusual 

 features ; though the remarkable terrace cut for the 

 accommodation of the railway under the steep slope of 

 Pemnaen Mawr is worthy of a passing notice. 



About midway between Conway and Bangor, Penmaen 

 Mawr forms a bold and almost precipitous headland, at 



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