The St. Johns herald., 1893-01-19
A MAMMOTH STRUCTURE.
The Wonderful Accomplishment of
 Mechanical Science.
How tho Great Building for Manufactures and Liberal Arts at the Worlds Fair Was Plxnned-A Monster
 Derrick.

n
 Derrick.
 It is in it's present stage of conStruc- tion that the mammoth building for the manufactures and liberal arts at the worlds fair is most curious and inter esting, says Harper's Weekly. They are now at work on the big derrick or traveller" as it is called. and the di.nen- sions of this engine arc suggestive of the tremendous proportions the building itself will assume as it hears compile tion. The great Eads bridge at St. Louis is a remarkable strJl ture, and one would fancy that buiiling con- taining more iron and steel than that embraced in its mighty arches must be a rare building indeed. In the manu- factures building will be used 400 tons more of metal than the amount used by Mir. Eads' engineers. New Workers know what Brooklyn bridge looks like. With the metal to be used in the .l3eral arts building two such bridges .su.l be built, and there would still ro-,a.ia as much as 2,400 tons unused. To bc more exact, upwards of 12,O00,000 pounds of steel and iron will be consumed by the constructionists in the If putting the liberal arts hall { ar
 The plans for this ,.a-5 extensive building ever attempi :. by 1lan were prepared by Mir. Ge ,.-e l. 1st, of New York. The truss, ..ii;5J w-i.l sup port the roof are the largest in the world. There will be a clear span of 3s6 feet from pillar to pillar. When the New Yorker stated that span of this proportion would be used, archi- tects and builders generally laughed at the idea, and said that this was ideal construction. But the enterprise was not submitted solely to builders of houses. It was point that was not all included in the studies of architecture. It more nearly approaches bridge en- gineering. This is true of more than one building planned for the Columbian exposition. The bridge engineers were consulted made their rcalcuIations, looked wise, closed their eyes as if in deep thought, and then pronounced: Ut can be done, but it will cost great fortune in dollars"
 
 worlds fair treasurer undertook to do the rest. The contracts were let to a Pittsburgh company, and now they are demonstrating the accuracy of the mathematics by literally doing the work.
 But there was another problem (and not small one) to be solved before the iron and steel were made ready. Given &ba rlarc ond %ba ynofar;a1 boxr, a0,,Id this 5000 tons of metal be lifted into position? There are 26 main trusses, each weighing 200 tons, and these are to form the bases for the roof spans. To lift mass of material weighing 200 tons, and to handle it with the pre- cision and accuracy necessary for the niceties of Mir. Posts plans, require no common enginery. And no common enginery is brought into play here. 1t was a month ago that the builders be- gan the work of constructing the engine which was to carry these immense masses of metal as easily as an athlete swings dumb-bell. It was now almost finished-a derrick 255 feet in height, and 36S feet in length. 1t is built with four uprights at the corners, that are jointed at sections of 40 feet by heavy cross beams, making the skeleton. For the stays are used as ropes of steel that are strung diagonally. Then there are V trusses that, being bolted and mortised to the cross beams, insure the strength of the structure.
 The ''traveler" rests on foundation as stable and as solid as may be. A strip of the great floor was torn up. and piles in three ows were driven in aiCng the line of the track which the derriv k is to follow. Caps of timber l2 inches square, on which are placed l00-Pound steel rails, make track. Purchase will be had in the great cranes that will be rigged on the top of the traveller. The heaviest tackle obtainable will be used in the working of these cranes. A stationary engine will be ,.sed to move the derrick along the trac cy.
 Now that this great oe.5,, x is ready it is expected that the :E iss will grow rapidly. In tl. s.. D. aration for the work is ~ s,r1at an undertaking as the .. ,sI.I.