miscellaneous.From the Scienttfn* American.Tin* World9* Fair.LoxdoNj May ICtb, lUtLouduu Illustrated New s has some very fiue biiit imaginary engravings of some works uf art exhibited at the fair, lt;ue thing rrpr^ Behind is a beautiful designed iron gate, which \bould attract the attention of our countrymen.I have seen seme eastings in iron here which surpass anything of the kind, 1 ever expected j |p see, and this gate is one of them. It is pla- j within the grand entrance, and forms u subsidiary bar, the scene beyond this gate is magnificent,—but let me pass on to describe something I have not yet in any of my letters described, this is the great diamond of Lahore, **the Mountain of Light. 1 his diamond is now the property of the crown of England; it ones sparkled in the coronet, it is said. lt;*t the princes of Persia. It is displayed in a machine formed for its reception hy Mr. Chubbs, the celebrated lock manufacturer, of London. This machine is impregnable. The diamond is let down into its recess at night, and raised for exhibition in the morning. Mr. Chubbs’ diamond c4ise is extremely ingenious, but nobody except the maker fully understands the mechanism. It has to defend property, valued at une million j Sterling, which might be slipped into one s pocket without greatly increasing its bulk. 1 This great diamond has an interesting history, jt was the property of Runjeet Singh during.bisiffc. The able Sikh leader had tw* estimatesc f its value. He knew its worth Jn money, but he knew also that it possessed influence w hicli money could not buy; for the Hindoos regarded it as the symbol of power and success, and it is worth ‘*ten thousand men'* to an ambitions prince. The political importance of “the Mountain of Light'’ induced its removal to England; bjit it is the greatest of the world s gems —the premier diamond that earth has yieldedveA.«