The Civil engineer and architect's journal, scientific and railway gazette (1839)
London : [William Laxton] · leaf 323
te proportions which extend to several places of decimals. For instance,at page 20 is explained how the compasses may be set to the proportion 1 : 31110, the ratio of the diameter of a circle to its circumference.These refined adjustments are perfectly unattainable with the old instru-ment. Iig. 1… … The principal feature of the invention is that the moveable centre E F,about which the two arms turn, is provided with a vernier, and that thepoints X, I/, are moveable and also provided with verniers. Beside this,there are tightening screws to fix all the points when they have been ad-justed. The…
Architecture · Civil engineering · Science
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