American architect and architecture Volume 22 - Softcover

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1887 Excerpt: ...and then the pieces exposed alternately to the tide-water and air, and thus intermittingly wet for a period of thirteen days, after which they were tested. The nails were not rusty when withdrawn, although the wood was apparently water-soaked as deep as the nails were driven. GOd nails were used, and spikes which were " square by 8" long, each were driven 4" into the wood. In white pine, stick B, the nails showed 199 pounds per square inch, the spikes 231 pounds per square inch resistance. In yellow pine, stick 1), the nails gave 488 pounds per square inch, the spikes 296 pounds per square inch resistance. In white oak, stick F, the nails gave 786 pounds per square inch, the spikes 458 pounds per square inch resistance. It will be seen that all of these results, with wet sticks, are below the corresponding resistances with dry wood. A number of experiments were made on the resistance of driving 60d nails perpendicular to the grain. These tests were made by slowly driving the nails with hydraulic power, and noting the force required. The maximum resistance to driving in white pine, stick B. was 391 pounds per square inch when the nails were driven 3", and 397 pounds per square inch when they were driven 4". In yellow pine, stick I), the resistances were 572 pounds per square inch, and 635 pounds per square inch for 3" and 4" depth of nail. It was observed that the resistance to penetration was not uniform, but varied as different layers of the wood were reached; at times the nails would continue to penetrate the wood under a less load than had previously been resisted, this variation being from five to ten per cent of the load. These experiments were few, and as there were no observations on pulling the same nails a compari...