Выпишите предложения в страдательном залоге, подчеркните глагол в форме Passive (можно еще перевести текст)... When the basic theory of static equilibrium for forces acting in any direction was first applied in structural design in the second half of the 18 th century, the criterion of a safe design seemed obvious enough. The structure would be safe if it could support its own weight, and perhaps the weight of a wagon passing over it, or of machinery on a floor, without overloading any crucial element — arch rib, beam, column, masonry pier, or tie rod. The strength of these elements could be assessed by loading specimens to failure, or by similarly loading specimens of the material if the strength of the element could then be estimated by simple proportion. For greater safety, some proportion. would be allowed on the measured or estimated strengths.