gannett.] GEOGRAPHIC TABLES AND FORMULAS. 253 
Table 24. — For obtaining differences of altitude for any minute, etc. — Continued. 
9° 
Corrections for curva- 
1 
2 
3 
4 
5 
6 
7 
8 . 
9 
ture, refraction 
and 
height of instruments 

836.3 
1,673 
2,509 
3,345 
4,181 
5,018 
5,854 
6,690 
7,526 
1 
837.8 
1,676 
2, 514 
3,351 
4,189 
5, 027 
5, 865 
6, 703 
7,541 
Miles. 
Feet. 
Miles. 
Feet. 
2 
839.4 
1,679 
2,518 
3,358 
4,197 
5, 037 
5, 876 
6,715 
7,555 
1.6 
6 
10.2 
64 
3 
841.0 
1,682 
2, 523 
3,364 
4, 205 
5, 016 
5,887 
6, 728 
7,569 
2.1 
7 
10.3 
65 
4 
842.6 
i,< ;s;, 
2, 528 
3,370 
4, 213 
5, 055 
5, 898 
6,741 
7,583 
2.5 
8 
10.4 
67 
5 
844.2 
1,688 
2, 532 
3,377 
4. 221 
5, 0(55 
5, 909 
6, 753 
7, 597 
2.8 
9 
10.5 
68 
6 
845.7 
1,691 
2, 537 
3, 383 
4,229 
5, 074 
5, 920 
6, 766 
7,612 
3.1 
10 
10.6 
69 
7 
847.8 
1,695 
2, 542 
3,389 
4,237 
5, 084 
5, 931 
6,778 
7, 626 
3.4 
11 
10.7 
70 
8 
848.9 
1,698 
2, 547 
3, 396 
4, 244 
5, 093 
5, 942 
6,791 
7,640 
3.6 
12 
10.8 
71 
9 
850.5 
1,701 
2, 551 
3, 402 
4, 252 
5,103 
5,953 
6,804 
7,654 
3.8 
13 
10.9 
73 
10 
852. 
1,704 
2, 556 
3,408 
4,260 
5, 112 
5,964 
6,816 
7,668 
4.1 
14 
11.0 
74 
11 
853. 6 
1,707 
2,561 
3,414 
4, 268 
5, 122 
5, 975 
6, 829 
7,683 
4.3 
15 
11.1 
75 
12 
855. 2 
1,710 
2,566 
3, 421 
4,276 
5, 131 
5, 986 
6, 842 
7,697 
4.5 
16 
11.2 
77 
x3 
856. 8 
1,714 
2, 570 
3,427 
4, 284 
5,141 
5,997 
6,854 
7,711 
4.7 
17 
11.3 
78 
14 
858.3 
1.717 
2, 575 
3, 433 
4, 292 
5, 150 
6, 008 
6,867 
7,725 
4.8 
18 
11.4 
79 
15 
859.9 
1,720 
2,580 
3,440 
4, 300 
5, 160 
6, 020 
6,879 
7,739 
5.0 
19 
11.5 
80 
16 
861. 5 
1, 723 
2, 585 
3,446 
4,308 
5, 169 
6, 031 
6,892 
7, 754 
5.2 
20 
11.6 
82 
17 
863.1 
1,726 
2, 589 
3, 452 
4,315 
5, 179 
6, 042 
6, 905 
7,768 
5.4 
21 
11.7 
83 
18 
864.7 
1,729 
2,594 
3, 450 
4, 323 
5,188 
6, 053 
6,917 
7,782 
5.5 
22 
11.8 
84 
19 
866.2 
1,732 
2, 599 
3,465 
4,331 
5,197 
6,064 
6,930 
7,796 
5.7 
23 
11.9 
86 
20 
867.8 
1,736 
2,603 
3,471 
4,339 
5, 207 
6, 075 
6, 943 
7,810 
5.8 
24 
12.0 
87 
21 
869. 4 
1,739 
2, 608 
3,478 
4,347 
5, 216 
6,086 
6, 955 
7,825 
6.0 
25 
12.1 
89 
22 
871.0 
1,742 
2, 613 
3,484 
4, 355 
5, 226 
6,097 
6,968 
7,839 
6.1 
26 
12. 2 
90 
23 
S72. 5 
1,745 
2, 618 
3,490 
4,363 
5, 235 
6, 108 
6, 980 
7, 853 
6.3 
27 
12.3 
91 
24 
874. 1 
1,748 
2, 622 
3, 496 
4,371 
5, 245 
6, 119 6, 998 
7,867 
6.4 
28 
12.4 
93 
25 
875.7 
1,751 
2, 627 
3, 503 
4,379 
5, 254 
6,130 
7,006 
7,881 
6.5 
29 
12.5 
94 
26 
877.3 
1,755 
2, 632 
3, 509 
4, 386 
5, 264 
6,141 
7,018 
7,896 
6.7 
30 
12.6 
96 
27 
878.8 
1,758 
2, 637 
3,515 
4,394 
5, 273 
6,152 
7, 031 
7,910 
6.8 
31 
12.7 
97 
28 
880.4 
1,761 
2,641 
3,522 
4,402 
5, 283 
6,163 
7,043 
7,924 
6.9 
32 
12.8 
99 
29 
882. 
1,764 
2,646 
3,528 
4,410 
5, 292 
6,174 
7,056 
7,938 
7.0 
33 
12.9 
100 
30 
883.6 
1,767 
2,651 
3,534 
4,418 
5, 302 
6,185 
7,068 
7, 952 
7.2 
34 
13.0 
102 
31 
885. 2 
1,770 
2, 656 
3,541 
4, 426 
5,311 
6,196 
7,081 
7,967 
7.3 
35 
13.1 
103 
32 
886.7 
1,774 
2,660 
3, 547 
4,434 
5,320 1 6,207 
7,094 
7,981 
7.4 
36 
13. 2 
105 
33 
888.3 
1,777 
2, 665 
3, 553 
4, 442 
5,330 ! 6,218 | 7,107 
7,995 
7.5 
37 
13.3 
106 
34 
889.9 
1,780 
2, 670 
3, 560 
4, 450 
5,339 1 6,229 7,119 
8,009 
7.6 
38 
13.4 
108 
35 
891.5 
1,783 
2, 674 
3, 566 
4, 457 
5,349 1 6,240 7,132 
8,023 
7.8 
39 
13.5 
109 
36 
893.1 
1,786 
2,679 
3,572 
4, 465 
5,358 1 6,252 
7, 145 
8,038 
7.9 
40 
13.6 
111 
37 
894. 6 
1,789 
2,684 
3, 579 
4,473 
5, 368 ' 6, 263 
7,157 
8,052 
8.0 
41 
13.7 
112 
38 
896. 2 
1,792 
2,689 
3, 585 
4,481 
5,377 | 6,274 
7,170 
8,066 
8.1 
42 
13.8 
114 
39 
897.8 
1,796 
2, 693 
3,591 
4,489 
5,387 
6,285 
7,183 
8,080 
8.2 
43 
13. 9 
115 
40 
899. 4 
1,799 
2,698 
3,598 
4,497 
5,396 
6,296 
7, 195 
8,095 
8.3 
44 
14.0 
117 
41 
901.0 
1, 802 
2, 703 3, 604 
4, 505 
5, 406 
6, 307 
7, 208 
8,109 
8.4 
45 
14.1 
119 
42 
902. 5 
1,805 
2,708 
3, 610 
4,513 
5, 415 
6, 318 
7, 220 
8,123 
8.5 
46 
14.2 
120 
43 
904.1 
1,808 
2,712 
3,617 
4, 521 
5, 425 
6, 329 
7, 233 
8,137 
8.6 
47 
14.3 
122 
44 
905. 7 
1,811 
2,717 
3, 623 
4, 529 
5,434 
6, 340 
7,246 
8,151 
8.7 
48 
14.4 
124 
45 
907.3 
1,814 
2, 722 
3,629 
4, 537 
5,444 
6, 351 
7,258 
8,166 
8.8 
49 
14.5 
125 
46 
908.9 
1,818 
2, 727 
3, 636 
4, 544 
5, 453 
6, 362 
7,271 
8,180 
8.9 
50 
14.6 
127 
47 
910. 5 
1,821 
2,731 
3, 642 
4, 552 
5, 463 
6,373 
7, 284 
8,194 
9.0 
51 
14.7 
129 
48 
912.0 
1,824 
2,736 
3,648 
4,560 
5, 472 
6,384 
7,296 
8,208 
9.1 
52 
14.8 
130 
49 
913.6 
1,827 
2, 741 
3,654 
4,568 
5,482 
6,395 
7,309 
8, 223 
9.2 
53 
14.9 
132 
50 
915.2 
1,830 
2,746 
3,661 
4,576 
5,491 
6,406 
7,322 
8,237 
9.3 
54 
15.0 
134 
51 
916.8 
1,833 
2,750 
3,667 
4,584 
5, 501 
6, 417 
7,334 
8, 251 
9.4 
55 
15.1 
135 
52 
918.4 
1,837 
2, 755 
3,673 
4, 592 
5, 510 
6, 429 
7,347 
8, 265 
9.5 
56 
15.2 
137 
53 
919.9 
1,840 
2,760 
3,680 
4,600 
5, 520 
6, 440 
7,360 
8, 279 
9.6 
58 
15.3 
139 
54 
921.5 
1,843 
2, 765 
3,686 
4,608 
5,529 i 6,451 
7, 372 
8, 294 
9.7 
59 
15.4 
141 
55 
923.1 
1,846 
2, 769 
3, 692 
4,616 
5,539 
6, 462 
7,385 
8,308 
9.8 
60 
15.5 
142 
56 
924. 7 
1,849 
2, 774 
3,699 
4, 623 
5, 548 
6,473 
7,397 
8,322 
9.9 
61 
15.6 
144 
57 
926.3 
1,852 
2,779 
3, 705 
4,631 
5,558 
6,484 
7,410 
8,336 
10.0 
62 
15.7 
146 
58 
927.8 
1,855 
2,784 
3,711 
4, 639 
5, 567 
6,495 
7, 423 
8,351 
10.1 
63 
15.8 
148 
59 
929.4 
1,859 
2,788 
3,718 
4,647 
5, 577 
6,506 
7,435 
8,365 
15.9 
16.0 
150 
151 
60 
931.0 
1,862 
2, 793 
3, 724 
4, 655 
5,586 6,517 
7,448 
8,379 
a For all distances under 1.6 miles the correction may be taken as + 5 feet, 
is assumed 4.5 feet. 
Height of instrument 
