152 



A MANUAL OF TOPOUKAPHIC METHODS. 



Table VII. — Differences of altitude from angles of elevation or depression. 



Difference of altitude = 



I + D/t! -f h.j for angles of elevation. 

 i — DA, + h 2 for angles of depression. 



D — distance in miles, a — angle of elevation or depression 

 /ii = 5280 ft. X tan a; A 2 — correction for curvature and 

 refraction. Argument for h t is a ; argument for h? is 1>. 



18° 14° 16° 



10.7 

 12.3 

 13.8 

 15.4 



16.9 



is I 

 20. t) 

 21.5 

 23. o 



35.3 



30.9 

 38.4 



101.4 

 102.9 

 104.4 

 106.11 

 107.5 



ll®. 1 

 110.6 

 112.1 

 113.7 

 115.2 



116.7 

 118.3 



119.8 

 121.4 

 122.9 



124.4 

 126. (I 



127. .". 



"ill. 7 

 52.2 

 53.8 



55.3 

 56.8 

 58.4 

 59.9 

 61.4 



63.0 

 64.5 



61) II 

 67.6 



1K0. 



1*7.4 

 ISO. 



ion. r. 

 192.1 



193.6 



195. 1 



196. 7 

 198. 2 

 199.8 



201.3 



202. 8 

 204. 4 

 2H5. 9 

 2n7. 5 



209. 301. 3 



210. 5 302. 9 



212.1 3 



213. 6 306. 



215. 1 307. 5 



278. 2 



279. 8 

 281.3 

 282. 9 

 284.4 



286.0 

 287. 5 

 2S9. 

 290.6 

 292.1 



293.7 



293,2 

 296. 7 



29s. :; 



41.5 

 43.0 

 44.5 

 46.1 



141.3 

 142.9 

 144.4 

 146. 



210.7 

 218.2 

 219.8 

 221.3 



222. 



224.4 

 22.".. 9 

 227. 4 

 229. ii 

 230.5 



232.1 



23s 2 



147.5 239. 



149.0 241.3 



150.6 242.8 



152.1 244.4 

 153.6 2(5.9 



153.2 

 1511.7 

 158.2 



159 - 



247. 5 



249. II 



250. 5 

 232. 1 



70.6 

 72.2 

 73.7 

 75.3 

 76.8 



78.3 

 79.9 

 81.4 



161.3 253.6 



162. 9 255. 1 



164.4 256. 

 165.9 258.2 



167.5 259.8 



169.0 261.3 



170.6 262.8 



172.1 264.4 



173.6 265.9 



175.2 267.5 



176.7 209. 



178.2 270.5 

 170. s 2 



181.3 273.6 

 182.9 275.2 

 184 4 276.7 



463. 5 



405. 



406. 6 

 468.1 



471.2 

 472. 8 

 474.3 

 475. 9 

 •477.4 



479.0 

 480.5 

 482. 1 

 483. 6 



4S5 2 



393. 9 486. 7 

 395.5 iss :; 

 397. 489. 8 

 491. 3 

 400. 1 492. 9 



378.5 

 380.0 

 381.6 

 383.1 

 384.6 



387.7 

 389. 3 

 3911.8 

 392. 4 



309. 1 



310. 6 



312. 1 



313. 7 

 315.2 



316.8 

 318.3 

 319.9 

 321. i 



322.9 



401.6 



403. 2 



404. 7 

 406. 3 

 407.8 



409. t 

 410.9 

 412.5 

 414.0 

 415.5 



417.1 



lis. 

 420. 2 

 421.7 

 423. 3 



332.2 424.8 

 333. 7 426. 4 



335. 3 427. 9 

 336. 8l 429. 5 



338.4 431.0 



339. 9, 

 341. 4 

 343.0 

 3 11 5 

 346.1 



347.6 



349. 1 

 350.7 



352. 2 

 353.8 



355.3 

 356.9 

 358.4 



300. 

 361.5 



363.0 

 364.6 

 366.1 

 367.7 



432.0 

 434.1 

 135 

 437. 2 

 438.7 



440.3 

 441.8 

 443.4 

 444.9 

 446.5 



448.0 

 449. 6 

 451.1 

 452. 7 

 454. 2 



455.8 

 457.3 

 458.9 

 460.4 

 401.9 



494.5 

 496. 

 497.6 

 499.1 

 500.7 



510. 

 511.5 

 513.0 

 514.6 

 516.2 



517.7 



519. 3 



520. 8 

 523 4 

 523.9 



527. 



528. 6 

 530. 1 

 531.7 



533.2 

 534. 8 

 536. 3 

 537.9 



53,9. 4 



541. 



542. 5 

 544 1 

 545. 1 

 517.2 



548.7 

 550, 3 

 551.8 

 553. 4 

 555. 



550. 5 

 558. 

 559 6 

 561.2 



572.0 

 573. 6 

 575. 1 

 576.7 

 578.2 



579.8 



581. 3 



582. 9 

 584 4 

 586.0 



587.6 



649.9 

 651.4 

 653 ii 

 654. 5 

 056. 1 



657.7 



Olis.O 

 670. 1 

 071 7 



073.3 707. 1 



674.8 70- 7 



070 4 770. 3 



077. 9 771.8 

 679. 5 773. 4 



743.0 

 745. 2 

 746.7 

 748.3 

 749.9 



7'1.4 



753. II 

 754.0 

 750 I 

 757.7 



762 1 

 705.0 

 705. 6 



681.1 



082. 



684.2 



088. 9 

 690.4 

 692 ii 



093.. 



099. 8 

 701.4 

 702. 9 



775. 

 770. 5 

 778.1 

 779. 7 

 781.3 



782.8j 

 784.4 

 786. 

 7.-7. 5 

 789.11 



790. 7 

 792.2 

 793.8 



795. I 

 797.0 



798. 5i 

 son. 1 

 801.7 



803. 2; 



804. 8 



837. 8 

 839 I 



841. 



842. 

 844.1 



845. 

 847.3 



848. 9 

 850 4 

 852. 



803. (I 

 864. 6 



800. 2 

 867.8 



875. 



877.3 

 878.8 

 880.4 

 382 " 

 883.6 



885.1 



932.6 1027.9 



934.2 1029.5 



935.8 1031.1 



937.3 1032.7 



938.9 1034.3 



940.5 

 942. 1 

 943.7 



945. 3 



946. 8 



91s I 



950. 



951. 



953.2 

 951. 7 



1123,9 



1125.5 



1127.1 



1128. 



1130.3 



1131.9 

 II 13.5 

 1135.2 

 1136 



1138.4 



1220. 

 1222 

 1323. 8 

 1225.5 



1227. 1 



1228. 7 



12311.3 

 1231.9 



1333 

 1235. 2 



1318.1 

 1319. 

 1321.3 

 1323. II 

 1324 



1416.4 

 1418 11 

 1419.7 

 1421.3 

 1423.0 



1320.2 1424.0 



1337 9 1423,, 



1329. 5 1427. 9 



1331.1 1429.0 



1332.8 1431.2 



1043,8 

 11145.4 

 1O17.0 

 1048. 

 1050.2 



956. 3' 1051.8 



957.9 1053.4 



959.5 1055.11 



961.1 1056.6 



903.7 11158.3 



114O.0 1230.8 1334.4 1432.9 



1141.6 1238.4 1335.0 1434.5 



1143. 2 1240.0 1337.7 1430.: 



1144 8 1241.7 1339.3 1437.1 



1146.4 1243.3 1340.9 1439.5 



HIS 1244.9' 1342.6 1441.1 



1149.6 1210 5 1344.2 1442 



1151.2 1248. 1 1345.8 1444.4 



1152.8 1249.8 1317.5 1440, 1 



1154.4, 1251.4, 1349.1' 1447.7 



964.3 1059.8 1150.1 1253.0 1350.8 1449.4 



965.9 1001.4 1157.7 1254.0 1352.4 1451.0 



907.5 lll03.ll 1159.3 1350.2 1354.11 1452.7 

 969.0, 1064.6 1160.9' 1257.9 1355.7 1454.4 



970.6 1066.2 1102.5 1259.5 1357.3 1450. II 



973.2 1 1 107. 8 



973.8 1069.4 



975.4 1071.0 



977.0 1072.6 



978.6 1074.2 



1164.1 1261.1 



1165.7, 1162.7 



1107.3 1264.4 



1108.9 1266.0 



1170.6 1267.6 



980.1 1075.8 1172.2 



981.7 1077.4 1173.8 



983.3 1079.0 1175.4 



984.9 1080.6 1177.0 



986.5 1082.2 1178.6 



988.1, 1083.8 



989.7 1085.4 



991.3 1087.0 



992.9 1088.6 



994.5 1090.2 



900. 9 996. 



902. 5 997. 6 



904. 1 999. 2 



9115 7 1 .8 



907.3 1002.4 



908.8 1004.0 



910.4 1005.6 

 912.0 1007.2 

 913.6, 1008.8 



915.2 1010.4 



916.7 1012.0 



918.3 1013.6 

 919. 9' 1015.2 



1016. 8 

 1018.4 



1020. 

 1021.5 

 1023. 1 

 11124.7 



1020.3 



937. 8 

 929. 4 

 931.0 



127 



1358.9 1457.7 



1300.0 1459.3 

 1302.2 1401.0 

 1303,9 1402. 

 1365. 5J 1464.3 



1367.1 1465.9 

 1368.8 1467.6 

 1370.4 1469.2 

 1372.1 1470.9 

 1373.7 1472.5 



1180.2 1277 4 



1181.8 1279,0 



1183.4 1280.0 



1185.0 1282. 



1186.7' 1283.9 



1091,8 

 1093.4 



1O95.0 



1188.3 

 1189.9 

 1191.5 



13S5. 5 

 1287. 1 

 1288. s 

 1290.4 



1292. 



1293. 7 

 1295. 

 1296. 



1298. 5 

 1300 2 



1301.8 

 1303.4 



1305. II 



1306. 7 



1308. 3 



1309. 9 

 1311.6 



1313.2 

 1314.8; 

 1316.5 



1375. 3 



1377. 



1378. 6 

 13S0. 3 

 1381.9 



1383. 5 



1385.2 



1386.8 



138S.5 

 13911. 1 



1391. 8 



1393.4 

 1395 

 1396.7 

 1398. 3 



1474. 2 

 1475.9 



147 7 5 

 1479.2 

 1480. 8 



1482.5 

 1484. 1 

 1485. S 

 1487. 5 



1489. 1 



1490. 8 

 1492. 4 

 1494. 1 

 1495.8 

 1497. 4 



1403.3| 1502.4' 



1404. 9 1504. 1 



1406.5 1505.7 



1408. 2: 1507.4' 



1409.8 1509.0 



1410.5 1510 7 



1413.1 1512.4 



1414.8, 1514.0 



