562 APPENDIX. 



than the other; for, though the sum of the 

 strengths of the small links must be equal to 

 that of the bars as stated before, a much 

 smaller bolt will suffice; one of half the 

 section of one of the bars might perhaps be 

 sufficient, since to be broke it would have to 

 be shorn four times through; and it is found 

 by experiment to require a greater force to cut 

 a body across, in this manner, than to tear it 

 asunder longitudinally. 



In the bridge in question the bolts are in 

 some degree acted upon by leverage, and the 

 small middle links are no stronger than the 

 side ones; from these causes the joints A are 

 somewhat weaker than the rest of the chain, the 

 weakest part being in the middle of the joint, 

 and where one of the small links was found 

 long ago to have opened ; a circumstance which 

 was noticed in the additions to the paper on 

 this Bridge, in the present volume. 



The bridge is now opened again to the public, 

 having been repaired by the engineer. It is to 

 be regretted that the repairs have been too 

 restricted and economical; but great care has 

 been taken to remove any defective links, and 

 the ends of the chain have been considerably 

 strengthened. It seems not to have been con- 



