Figure 2-24 shows the triangular architect’sscale. Also shown are segments of each of theeleven scales found on this particular type of scale.Notice that all scales except the 16th scale areactually two scales that read from either left toright or right to left. When reading a scalenumbered from left to right, notice that thenumerals are located closer to the outside edge.On scales that are numbered from right to left,notice that the numerals are located closer to theinside edge.Architect’s scales are “open” divided (only themain divisions are marked throughout the length)with the only subdivided interval being an extrainterval below the 0-ft mark. These extraintervals are divided into 12ths. To make a scalemeasurement in feet and inches, lay off thenumber of feet on the main scale and add theinches on the subdivided extra interval. However,notice that the 16th scale is fully divided with itsdivisions being divided into 16ths.Now let’s measure off a distance of 1 ft 3 in.to see how each scale is read and how the scalescompare to one another. (Refer to fig. 2-24.) Sincethe graduations on the 16th scale are subdividedinto 16ths, we will have to figure out that 3 in.actually is 3/12 or 1/4 of a foot. Changing thisto 16ths, we now see we must measure off 4/16thsto equal the 3-in. measurement. Note carefully thevalue of the graduations on the extra interval,which varies with different scales. On the3 in. = 1 ft scale, for example, the space betweenadjacent graduations represents one-eighth in. Onthe 3/32 in. = 1 ft scale, however, each spacebetween adjacent graduations represents 2 in.The scale 3/32 in. = 1 ft, expressed fraction-ally, comes to 3/32 = 12, or 1/128. This is thesmallest scale provided on an architect’s scale. Thescales on the architect’s scale, with their fractionalequivalents, are as follows:Engineer’s ScaleThe chain, or civil engineer’s, scale, commonlyreferred to as the ENGINEER’S SCALE, isusually a triangular scale, containing six fullydivided scales that are subdivided decimally, eachmajor interval on a scale being subdivided into10ths. Figure 2-25 shows the engineer’s scale and142.321Figure 2-25.-Engineer’s scale.2-19