Where do elves get metal?

[Zigûr]

Originally Posted by William Cloud Hicklin

The Silvan Elves of course listened to Jethro Tull and indignantly insisted "They really are metal!"

My dad must be a Silvan Elf then.

Another rather obvious bridge I've missed is the one in The Hobbit itself that leads into Rivendell, one which appears to be of a defensive nature:

There was only a narrow bridge of stone without a parapet, as narrow as a pony could well walk on; and over that they had to go, slow and careful, one by one, each leading his pony by the bridle.

Incidentally, Dr. Rateliff is curious about this note of Professor Tolkien's after the end of the revised Chapter III:

Ch. III should make clear
Elrond's care for roads etc. from
Greyflood to <Mountains>

Dr. Rateliff finds this difficult because he does not consider there to be a precedent for Elves doing the road work and thinks it unlikely that Dwarves would have been hired to do it as "that solution runs afoul of this text's statement that dwarves were not welcome here [in Rivendell] and did not know this part of the world well."

However he seems to extrapolate a tad; the text simply says "This country was not well known to the dwarves" (previously "unknown to the dwarves" but Professor Tolkien himself realised this was inconsistent with the fact that they traded between the Iron Hills and the Blue Mountains by traversing that region, and so changed the statement) and says of Rivendell "few dwarves have ever seen it."

Dr. Rateliff takes this as meaning that "the dwarves were not particularly welcome at Rivendell", describing it as a "new and somewhat disconcerting idea, apparently imported back into The Hobbit to match the initially chilly relations between Gimli's people and the elves of Lórien in The Lord of the Rings." He observes that Professor Tolkien originally drafted "no dwarf has ever seen it" but changed it.

To me there are a few too many assumptions here; the idea that few Dwarves had seen Rivendell does not seem particularly "disconcerting" to me, as it does not seem to me that there would be much reason for the Dwarves to go there, or much reason for Elrond to compromise Imladris' secrecy by revealing its location to anyone except other Elves, the Wise and the Dúnedain. Surely if there was meant to be a parallel with Gimli's treatment in Lórien the Elves in the revised Hobbit would have been far more secretive, but they are not. I always assumed that the Silvan Elves of Lórien were simply a little superstitious. I find it unlikely that the Noldor of Imladris bore such prejudices given their history of collaboration with the Dwarves. I assume there were some Sindar at Rivendell as well, but nonetheless I think Dr. Rateliff is making the situation more complex for himself than is necessary. It could quite simply be that Elven craftsmen ventured forth, in secrecy, and maintained the roads when necessary.