1849.] Note on Iron Tension Bridges. 249 



salvation. The Hindu sages however maintain " rajaguna" (the qua- 

 lity of passion) and not " tamas" (darkness or vice) to be the cause of 

 transmigration ; but as the consequences of both rajas and tamas are 

 borne in inferior states of existence, which necessarily imply repeated 

 birth, the disagreement is not of any great importance." — J. W. L. 



Note on Iron Tension Bridges, by the Rev, J. H. Pratt. 



To the Editors of the Journal of the Asiatic Society. 



Since my return to Calcutta after an absence of four months I have 

 observed that my friend Major Goodwyn has forwarded to you an 

 article on Iron Tension Bridges, which you have printed in your number 

 for October last. In this article he does me the favour of noticing with 

 approval the Memoir I sent you at the beginning of the same year, on 

 the " Quantity of Iron necessary in a Tension Chain Bridge." 



The sole object of my troubling you with the present brief commu- 

 nication, is to point out that Major Goodwyn has made my Memoir 

 say more than I intended it should. In his para. 2 he observes as 

 follows upon the property which I had demonstrated : — 



" 2. This is a very important conclusion; but whilst I freely admit the 

 soundness of the doctrine, I am not fully satisfied as to the correctness 

 of the writer's practical deductions therefrom ; viz. that the old system 

 of suspension, consisting of a uniform chain and vertical drop-bars, is 

 the most proper for adoption under all circumstances." (See p. 413, 

 Vol. for 1848 ; the italics are mine.) 



But I have taken only one circumstance into account in my Memoir, 

 and have pronounced an opinion upon that only ; viz. the consideration 

 of the quantity of metal employed in the construction of the Bridge. 

 Some persons had strongly asserted that one advantage of the new 

 system was considerable economy of metal. This gave an importance to 

 the conclusion to which my calculation led. 



In endeavoring to come to a decision upon the merits of the Taper- 

 Chain system, when compared with the Common Chain, there are several 

 considerations which must be borne in mind and well examined — such 

 as regard, for instance, the elegance of the structure, the convenience 



2 k 2 



