458 On the comparative Strength of' Chain Cables. 



the link in the same sectional plane, Capt. Brown's links are 

 made of a twisted form, for the avowed purpose of giving them 

 elasticity— -a form extremely injurious to the strength of the link, 

 as the first effort of tension must be to draw the link out of its 

 twist, and bring those portions of it which lie between the points 

 of strain into straight lines. 



John Knowles, Esq. secretary to the surveyors of the navy, 

 gave a mo^t interesting detail of experiments made by order of 

 the Navy-office, to ascertain the comparative merits of Brown's 

 chain-cables and those of the patentee. In every experiment. 

 Brown's twisted links, with sharp-ended stays, were ruptured 

 and broken, while the plaintiff's remained uninjured. In conse- 

 quence, orders were issued that no more chain-cables on Brown's 

 construction should be admitted for the service of the navy; but 

 only and exclusively, chain-cables with broad-ended stays in the 

 links, and the links having their substance in the same plane. 



Mr. Knowles read the minutes of the experiments alluded to, and 

 which were signed by the commissioners of the navy, as follows: 



" At a trial of chain and hempen cables on the 23d of May, 

 IS 16, at the manufactory of Messrs. Brunton and Co., in the 

 Commercial Road. Present: 



The Comptroller of the navy. 

 Sir H. Peake. 

 Seppings. 

 Commissioners. <( Bowen. 

 Fraser. 

 Cunningham. 

 And the following were the results : — 



Experiment I. " Chain-cables of 1 \ inch diameter* manu- 

 factured from the same iron on Capt. Brown's twisted prmciple, 

 and on Messrs. Brunton, Middleton, and Company's plan, were 

 attached together. Capt. Brown's chain measured 36 feet, 

 Messrs. Brunton and Company's 33 feet. At a strain of 50 tons 

 the former had stretched 12 inches, the latter 6. On a strain 

 of 60 tons having been applied, the former had stretched 24 

 inches, and the latter 12. Capt. Brown's Avas broken in the body 

 of the iron by a strain of 65 tons; the iron was of a very good 

 quality: the stays of the twisted chain were generally crooked." 

 Experiment 2. " Capt. Brown's 1| inch chain, 36 feet long, 

 was attached to Messrs. Brunton and Company's \~ inch that 

 had before been tried [in Exper. 1.]. Capt. Brown's was broken 

 by a strain of 76 tons, a second link was fractured, and most of 

 the stays crooked." 



Lord Chief Justice Abbott. — " The other stood ? A. " Yes, 

 my lord." 



* That is the diameter of the iron of which the links were made. 



Expe- 



