expressed fractionally as 1/2, or it could be given as 1 in.   =  2  in.,  or  as  6  in.  =  1  ft. In this case, you made a drawing on a smaller scale than the scale of the original object, the scale of  an  original  object  being  always  1/1,  or  unity. The  relative  size  of  a  scale  is  indicated  by  the fractional  representation  of  the  scale.  A  scale whose fractional representation equals less than unity is a less-than-full scale. One whose fractional representation is greater than unity (such as a scale of  200/1)  is  a  larger-than-full  scale.  A  scale  of 1/10,000  is,  of  course,  smaller  than  a  scale  of 1/100. A scale expressed as an equation can always be expressed as a fraction. For example, the scale of  1  in.  =  100  ft,  expressed  fractionally,  comes to  1  over  (100  x  12),  or  1/1,200. It is obvious that any object that is larger than the drawing paper on which it is to be represented must be “scaled down” (that is, reduced to less- than-full   scale)   for   graphic   representation. Conversely,  it  is  often  desirable  to  represent  a very  small  object  on  a  scale  larger  than  full scale  for  the  purpose  of  clarity  and  to  show small  details.  Because  the  drawings  prepared by   an   EA   frequently   require   scaling   down, the  following  discussion  refers  mostly  to  that procedure.  However,  scaling  up  rather  than down  simply  means  selecting  a  larger-than-full scale rather than a smaller-than-full scale for your drawing. You   could,   if   necessary,   determine   the dimensions  of  your  drawing  by  arithmetical calculation; for example, on a half-scale drawing, you  divide  each  of  the  actual  dimensions  of  the object  by  2.  However,  this  might  be  a  time- consuming process if you were drawing a map of a  certain  area  to  a  scale  of  1  in.  =  1,000  mi,  or 1/6,335,000   ft. Consequently,   you   will   usually   scale   a drawing up or down by the use of one or another of a variety of scales. This sense of the term scales refers  to  a  graduated,  rulerlike  instrument  on which  scale  dimensions  for  a  drawing  can  be determined  by  inspection. Scales vary in types of material, shapes, style of  division,  and  scale  graduations.  Good  quality scales are made of high-grade boxwood or plastic, while inexpensive scales are sometimes made of 45.831 Figure 2-23.-Types of scales in cross section. yellow hardwood. The boxwood scales have white plastic scale faces that are permanently bonded to  the  boxwood.  The  graduation  lines  on  the boxwood   scales   are   cut   by   a   highly   accurate machine.  Plastic  scales,  while  less  expensive  than boxwood  scales,  have  clear  graduations  and  are reasonably  accurate. Scales  are  generally  available  in  four  different shapes, as shown in figure 2-23. The numbers in the figure indicate the location of the scale face. The  triangular  scale  provides  six  scale  faces  on one  rule.  The  two-bevel  flat  scale  provides  two scale  faces  on  one  side  of  the  rule  only.  The opposite-bevel flat scale provides two scale faces, one on each side of the rule. And the four-bevel flat scale provides four scale faces, two on each side of the rule. The most common types of scales are the architect’s, the engineer’s, the mechanical engineer’s,  and  the  metric.  All  of  these  scales are  found  in  the  EA’s  draftsman  kit  with  the exception   of   the   mechanical   engineer’s   scale, which  is  primarily  used  by  machine  draftsmen. To   gain   a   better   understanding   of   the architect’s  and  engineer’s  scale,  which  will  be described  in  the  following  sections,  it  may  be helpful to have the actual scales at hand as you study. Architect’s Scale ARCHITECT’S   SCALES   are   usually   tri- angular   in   shape   and   are   used   wherever dimensions  are  measured  in  feet  and  inches. Major  divisions  on  the  scale  represent  feet  which, in   turn,   are   subdivided   into   12ths   or   16ths, depending  on  the  individual  scale. 2-17