LESSON 6 
ENLARGING AND REDUCING PLANS 
to enlarge or reduce plans or maps, that is how 
to redraw them at a larger or a smaller scale. 
. There are several methods of doing the work, 
any one of which may be used for either enlarg- 
ing or reducing. Some of the methods are sim- 
ilar to those used in making surveys, for sur- 
veying is simply reducing a plan from full size to some smaller scale. 
‘ Cross-Section Method 
The plan to be enlarged or reduced is ruled off with two sets of 
parallel lines at right angles to each other equally spaced, usually 
at some multiple of five or ten feet apart at the scale of the plan. 
The lines in one direction are numbered and those in the other di- 
rection lettered. The sheet on which the enlargement or reduction 
is to be made is then ruled off in the same way, the lines being spaced 
relatively the same distance apart, that is the same number of feet 
apart at the new scale and numbered and lettered as on the original 
plan. The lines and objects of the plan are then drawn in each 
square in their relative positions, the distances being scaled or es- 
timated depending on the accuracy required. This method is 
similar to a cross-section survey. 
The Radial Method 
A transparent paper or cloth is firmly tacked down over the 
plan so that they will not move on one another. A point, usually 
somewhat central in location, is then taken from which the distance 
is measured, at the scale of the original, along a straight line to any 
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