The Use of the Abney Hand Level. 371 



grees based on horizontal distances expressed in paces, chains, or 

 any other equivalent. For our use I prefer the Abney level gradu- 

 ated in per cents and prefer to express distances in double paces 



TABLE FOR USE OF ABNEY LEVEL. 

 Slope 

 in 

 % Distance in Paces (5.28') 



15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 



200 5 5 5 5 5 5 5 5 5 5 10 10 10 10 10 10 



455 5 5 5 10 10 10 10 10 15 15 IS 15 20 20 20 20 



6 5 5 10 10 10 10 15 15 15 20 20 20 25 25 25 25 30 30 



8 5 10 10 10 15 15 20 20 20 25 30 30 30 30 35 35 40 40 



10 10 10 15 15 20 20 25 25 30 30 35 3,5 40 40 45 45 50 50 



12 10 10 15 20 20 25 30 30 35 35 40 45 45 50 50 55 60 60 



14 10 15 20 25 25 30 35 35 40 45 so so 55 60 65 65 70 75 



16 10 IS 20 25 30 30 35 40 45 50 55 60 60 65 70 70 75 85 



18 15 20 25 30 35 40 45 50 50 55 60 65 70 75 80 85 90 95 



20 15 20 25 30 35 45 50 55 60 65 70 75 80 85 90 95 100 105 



22 20 25 30 35 40 45 50 55 60 70 75 85 85 90 100 105 no 115 



24 20 25 30 40 45 50 55 65 70 75 80 90 95 105 no 115 120 125 



26 20 25 30 40 50 55 60 65 75 80 90 95 100 105 115 120 125 135 



28 20 30 35 45 50 60 65 75 80 90 95 105 no 115 125 130 140 145 



30 25 30 40 50 55 65 70 80 85 95 100 no 115 125 130 140 150 155 



32 25 35 45 50 60 65 75 8s 90 100 no 115 125 130 140 150 155 165 



34 25 35 45 55 60 70 80 90 100 105 115 125 130 140 150 160 165 180 



36 30 35 45 55 65 75 85 90 100 no 120 130 140 150 155 165 17S 185 



38 ^0 40 50 60 70 80 90 100 no 120 130 140 150 160 165 175 185 195 



40 30 45 55 6s 75 85 95 105 115 125 13S i45 I55 165 i75 185 195 205 



42 35 45 55 6s 75 85 100 no 120 130 140 150 160 170 180 195 205 215 



44 35 45 55 70 80 95 105 115 125 135 150 160 170 180 195 205 216 230 



46 35 50 60 75 85 95 no 120 130 14s iss 165 180 190 205 215 225 240 



48 35 50 65 75 85 100 no 125 135 150 160 175 185 200 210 220 235 250 



50 40 55 65 80 90 105 115 130 145 155 165 180 190 205 220 230 245 260 



52 40 65 70 80 95 no 125 140 150 165 180 190 205 220 235 245 260 275 



54 45 55 70 85 100 no 130 145 153 170 185 200 215 225 245 255 270 285 



56 45 60 75 90 105 115 13s 150 160 175 195 205 220 235 250 260 280 295 



58 45 60 75 95 no 120 140 155 170 185 200 215 230 245 260 275 290 305 



60 50 65 80 95 no 125 140 160 17s 190 210 220 240 250 270 285 300 315 



64 50 70 8s 100 no 135 150 170 185 200 220 235 250 270 290 305 320 335 



68 55 70 90 no 125 140 160 180 195 215 23s 250 270 285 305 325 340 360 



72 6b 75 95 115 13s 150 17s 190 210 225 250 26s 285 300 325 340 360 380 



76 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 350 380 405 



80 65 85 105 130 150 170 190 210 230 250 27s 29s 315 335 360 385 400 42s 



84 65 00 no 13s 155 175 195 220 245 26s 290 310 330 340 380 400 420 445 



88 70 90 IIS 140 160 185 205 235 255 275 305 32s 345 370 395 420 440 465 



90 70 95 115 14? 165 190 210 240 260 285 310 335 355 380 405 425 450 475 



(equal to 5.28 feet). It will be noticed that the elevation table 

 gives the reading in the nearest 5 feet, vi^hich was found to be 

 sufficiently accurate for all practical purposes. Thus using the 

 multiple of 5 for elevations, makes mental calculation easy. Any 

 error introduced by reading the elevation closer than 5 feet is 

 very small, for all such errors are compensating. The per cent 



