Cyclopedia of mechanical engineering; a general reference work Editor-in-chief Howard Monroe Raymond Assisted by a corps of mechanical engineers, technical experts, and designers of the highest professional standing . educing all the dimen- isions in the same proper- ition is to choose a certain |distance and l^t that dis- ;tance represent one foot, |this distance is then di-vided into twelve partsand each one of these ]tarta irejiresents an incli; thenif half and quarter inches ,are re(|nired these twilfthaare sul)divided into halves,quarters, etc., until the .subdivisions become sosmall that
Cyclopedia of mechanical engineering; a general reference work Editor-in-chief Howard Monroe Raymond Assisted by a corps of mechanical engineers, technical experts, and designers of the highest professional standing . educing all the dimen- isions in the same proper- ition is to choose a certain |distance and l^t that dis- ;tance represent one foot, |this distance is then di-vided into twelve partsand each one of these ]tarta irejiresents an incli; thenif half and quarter inches ,are re(|nired these twilfthaare sul)divided into halves,quarters, etc., until the .subdivisions become sosmall that they cannot be ?used. We now have ascale which represents thecommon foot rule with itssubdivisions into inchesand fractions; but our ilewfoot is smaller than theordinary distance whichwe call a foot, and ofcourse its subdivisions areproportionately we make a measure-ment on the drawing wemake it with our reducedfoot rule and when we make a measurement on the machine itselfwe make it with the common foot rule. Draftsmens scales can be bought which have different dis-tances thus divided, so tliat if the draftsman wishes to draw one-fourth size he looks over his scale until he finds a dis-. scale:-3 = i MECHAJSICAL DRAWING 3) tance of three inches (which is of course one-fourth of a foot)divided as explained above, and he uses this to measure with onhis drawing. His drawing MOTild then be made to a scale ofthree inches to the foot. In the same way, if he wishes to makehis drawing one-twelfth size he finds on his scale one inch dividedinto twelfths and fractions of twelfths and uses this as his standardof measurement; if he wishes to make his drawing one forty-eighth size he uses a quarter inch with its subdivisions. Some-times if the piece to be drawn is very small, the drawing is madeat an enlarged scale, such as twice size, three times size, etc. The mistake of choosing the wrong distance to use on a scaleis oiteu made. For example, if he wishes to draw a p
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmechanicalengineerin
