Scale Vernier Unit Test Plate Ott's K.&E., No. 4230 Coradi's Compensating No. Ratio Linear Area Actual Relative Area Reading Setting Constant Setting Constant Setting Constant Setting Constant 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 No. Ins. Ins. Ins. Miles Sq. In. Acres Sq. In. Acres Acres Units ½ mm Units ½ mm Units ½ mm Units ½ mm Units 1 1:120 120    = 1 1=    .0444 .01575 .0007 .6888 984 329.8 17341 24.2 18198 334.7 22602 _ _ _ _ _ _ _ _ 2 1:792 80    = 1 1=    .10 .01 .001 1.55 1550 217.6 19221 145.3 19308 212.6 25795 _ _ _ _ _ _ _ _ 3 1:1056 60    = 1 1=    .1777 .01406 .0025 2.7555 1102.2 297.1 17519 59.6 18174 298.8 22994 _ _ _ _ _ _ _ _ 4 1:1584 40    = 1 1=    .40 .0125 .005 6.20 1240 266.0 17868 92.6 18356 265.6 23683 _ _ _ _ _ _ _ _ 5 1:1980 32    = 1 1=    .625 .016 .01 9.687 968.7 334.8 17339 18.9 18218 340.1 22564 _ _ _ _ _ _ _ _ 6 1:3168 20    = 1 1=  1.6 .0125 .02 24.80 1240 266.0 17868 92.6 18356 265.6 23683 _ _ _ _ _ _ _ _ 7 1:3960 16    = 1 1=  2.5 .01 .025 38.75 1550 217.6 19221 145.3 19308 212.6 25795 _ _ _ _ _ _ _ _ 8 1:5280 12    = 1 1=  4.444 .01575 .07 68.8888 984 329.8 17341 24.2 18198 334.7 22602 _ _ _ _ _ _ _ _ 9 1:6336 10    = 1 1=  6.4 .0125 .08 99.2 1240 266.0 17868 92.6 18356 265.6 23683 _ _ _ _ _ _ _ _ 10 1:7920 8    = 1 1=10.0 .01 .10 155.0 1550 217.6 19221 145.3 19308 212.6 25795 _ _ _ _ _ _ _ _ 11 1:10560 6    = 1 1=17.777 .01406 .25 275.55 1102.2 297.1 17519 59.6 18174 298.8 22994 _ _ _ _ _ _ _ _ 12 1:12672 5    = 1 1=25.0 .01562 .40 396.8 992 327.3 17343 26.8 18194 332.0 22617 _ _ _ _ _ _ _ _ 13 1:15840 4    = 1 1=40.0 .01 .40 620.0 1550 217.6 19221 145.3 19308 212.6 25795 _ _ _ _ _ _ _ _ 14 1:21120 3    = 1 1=71.11111 .01406 1.0 1102.22 1102.2 297.1 17519 59.6 18174 298.8 22994 _ _ _ _ _ _ _ _ 15 1:25344 2½ = 1 1=    .16 Sq. M. .0125 .002 2.48 Sq. M. 1240 266.0 17868 92.6 18356 265.6 23683 _ _ _ _ _ _ _ _ 16 1:12672 5    = 1 1=    .04    " .01 .0004 .62    " 1550 217.6 19221 145.3 19308 212.6 25795 _ _ _ _ _ _ _ _ 17 1:6336 10    = 1 1=    .01    " .01 .0001 .155  " 1550 217.6 19221 145.3 19308 212.6 25795 _ _ _ _ _ _ _ _