File:Architect and engineer (1934) (14578041497).jpg

Identifier: architectenginee11935sanf (find matches)
Title: Architect and engineer
Year: 1905 (1900s)
Authors:
Subjects: Architecture Architecture Architecture Building
Publisher: San Francisco : Architect and Engineer, Inc
Contributing Library: San Francisco Public Library
Digitizing Sponsor: San Francisco Public Library

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factor, even as highas 20 per cent, does not put an impossibleburden on the structure and for that reasonwe all usually design our lower buildingssay up to six or eight stories with rigidresisting units. As we get higher than that,a high seismic factor becomes a very severeand often impossible burden and we areforced to depend to a large extent on theflexibility of the structure to resist earth-quakes. We do not always admit in somany words that we are relying on theflexibility of the structure, nevertheless, thatis the tacit assumption. In view of thefact that we have not experienced the col-lapse of a tall building, either in the northor south, we are entirely justified in design-ing on that basis. If we adopt this suggestion of the north-ern committee, the seismic factors on firmground will vary from 2 to 10 per cent de-pending on the rigidity of the resistingunits and similarly on soft ground from 5to 10 per cent. THE ARCHITECT AND ENGINEER ^ 25 ► NOVEMBER, NINETEEN THIRTY-FOUR
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THE ARCHITECT AND ENGINEER 4 26^ NOVEMBER, NINETEEN THIRTY-FOUR Termites Swarming Timeby A. A. Brown, C. E. K VIDENCES of subterranean termite attack are not easilydiscovered because of the concealed lifeof these insects. However, their presenceis indicated by the periodic emergence ofthe swarming alates usually in bright sun-light following the first fall rains, revealingin general the location of active colonies.Termites with fully developed wings beganto appear in colonies broken into by thewriter in late July and have been increasingin numbers as the fall months approached.A colony of these insects will usually befound to contain thousands of winged in-dividuals. These remain in the subter-ranean quarters with the workers forweeks, and even months, awaiting the firstheavy autumnal rain When that has fal-len and the soil is thoroughly soaked, theinsects crowd to openings provided by theworkers, and on the first clear day that fol-lows the rain, if the temperature is not toocool, th

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