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OS7000 Zeutschel, 400 dpi, 8 bit, 15,854,980 bytesNo rivet hole shall exceed diameter of rivet by more than one-sixteenth of an inch. Use of drift pins will not be allowed, except for bringing pieces into alignment, and reaming must be resorted to where necessary. Rivets must completely fill the holes, have full heads concentric with the rivet, and of a height not less than 0.6 the diameter of the rivet, and in full contact with the surface, and machine driven where practicable. LUMBER. The floor and joist furring will be of native pine. The floor shall be of 3 by 12 plank surfaced on one side to a uniform thickness and spiked to the furring strips with 2-60 D spikes to each plank at each intersection. The furring strips are to be 3 by 6 inches, surfaced one side, and bolted to top flange with 3/8-inch bolts spaced about 3 feet centers, staggered. No wheel guards will be used. The handrail will be of steel, consisting of angles latticed together and riveted to truss, as heretofore specified. PAINTING. All structural steel shall be given one coat of graphite paint at the shop and one additional coat of same paint after erection. All surfaces that will be inaccessible after assembling must be painted before the parts are assembled. INSPECTION. The work will be inspected by a representative of the Government while in progress of erection and must be completed to his satisfaction. EARTH FILL. The earth fill will not be included in bridge contract.--Specifications for furnishing and erecting a steel highway bridge over the Gila River near San Carlos, Ariz. The site for proposed bridge is about 6 miles north and east of San Carlos, Ariz., a station on the Southern Pacific Railroad. It is the duty of the bidders to acquaint themselves with the general local conditions. Bid must be accompanied by stress diagrams and preliminary design of the whole structure in duplicate. The successful bidder, when notified, must submit a complete set of shop detail drawings, which must be approved by the Commissioner of Indian Affairs before commencing work. The work included in this project is the building complete and ready for use of seven 138-foot steel spans with a 16-foot roadway, two concrete abutments, and six tubular piers as shown on the accompanying plans. LOADING AND UNIT STRAINS. The loading and unit strains assumed shall be in strict accordance with requirements for class C bridges as per Theodore Cooper's ‘‘Specifications for Steel Highway and Electric Steel Railway Bridges and Viaducts,’’ 1909 edition, except that the concentrated load assumed shall be 15 tons instead of 12 tons. The filling and grading of the approaches are not included in this project, and will be done by the United States Government after completion of the bridge. SUBSTRUCTURE. The substructure will consist of two concrete abutments and six tubular piers as heretofore stated. The abutment at the south end will be excavated into the ground to the depth shown and placed upon piles. The abutment at the north end will rest on the natural bedrock, which rock shall be excavated about 1 foot for reception of sam