gannett] GEOGRAPHIC TABLES AND FORMULAS. 257 
Table 24. — For obtaining differences of altitude for any minute, etc. — Continued. 
13°. 
Corrections for 
curva- 
1 
2 
3 
4 
5 
6 
7 
8 
9 
ture, refraction, and 
height of instruments 
/ 

1,219 
2,438 
3,657 
4,876 
6,095 
7,314 
8,533 
9,752 
10,971 
1 
1, 221 
2, 441 
3,662 
4,882 
6, 103 
7, 324 
8,544 
9,765 
10, 985 
Miles. 
Feet. 
Miles. 
Feet. 
2 
1, 222 
2, 444 
3,667 
4,889 
6,111 
7,333 
8,556 
9, 778 
11, 000 
1.6 
6 
10.2 
64 
3 
1,224 
2, 448 
3, 672 
t,895 
6, 119 
7,343 
8, 567 
9,791 
11,015 
2.1 
7 
10.3 
65 
4 
1,225 
2,451 
3,676 
4,902 
6, 127 
7, 353 
8,578 
9,804 
11, 029 
2.5 
8 
10.4 
67 
5 
1,227 
2, 454 
3,681 
4, 908 
6,135 
7,362 
8, 590 
9,817 
11,044 
2.8 
9 
10.5 
68 
6 
1,229 
2, 457 
3,686 
4, 915 
6,143 
7, 372 
8, 601 
9,830 
11,058 
3.1 
10 
10.6 
69 
7 
1,230 
2, 461 
3,691 
4, 921 
6, 152 
7,382 
8, 612 
9,843 
11,073 
3.4 
11 
10.7 
70 
8 
1,232 
2, 4(i4 
3, 696 
4, 928 
6, ItiO 
7,392 
8, 624 
9, 855 
11,087 
3.6 
12 
10.8 
71 
9 
1,234 
2,467 
3,701 
4,934 
6,168 
7,401 
8,635 
9,868 
11,102 
3.8 
13 
10.9 
73 
10 
1, 235 
2,470 
3,706 
4,941 
6,176 
7,411 
8,646 
9,881 
11,117 
4.1 
14 
11.0 
74 
11 
1,237 
2,474 
3,710 
4,947 
li, IS} 
7, 421 
8,658 
9,894 
11,131 
4.3 
15 
11.1 
75 
12 
1,238 
2, 477 
3, 715 
4, 954 
6, 192 
7,430 
8, 669 
9, 907 
11,146 
4.5 
16 
11.2 
77 
13 
1,240 
2,480 
3, 720 
4,960 
6,200 
7,440 
8,680 
9, 920 
11,160 
4.7 
17 
11.3 
78 
14 
1,243 
2,483 
3,725 
4, 967 
6,208 
7, 450 
8, 692 
9,933 
11,175 
4.8 
18 
11.4 
79 
15 
1,243 
2, 4S7 
3,730 
4,973 
6, 216 
7,460 
8,703 
9,946 
11,190 
5.0 
19 
11.5 
80 
16 
1, 245 
2, 490 
3,735 
4,980 
6,224 
7, 469 
8,714 
9, 959 
11,204 
5.2 
20 
11.6 
82 
17 
1,247 
2,493 
3,740 
4,986 
6, 233 
7,479 
8, 726 
9, 972 
11,219 
5.4 
21 
11.7 
83 
18 
1,248 
2, 496 
3,744 
4,993 
6, 241 
7,489 
8,737 
■ 9, 985 
11,233 
5.5 
22 
11.8 
84 
19 
1,250 
2,500 
3, 749 
4, 999 
6,249 
7,499 
8,748 
9,998 
11,248 
5.7 
23 
11.9 
86 
20 
1,251 
2,503 
3,754 
5,006 
6,257 
7,508 
8,760 
10, Oil 
11,262 
5.8 
24 
12.0 
87 
21 
1,253 
2, 506 
3, 759 
5,012 
6,265 
7,518 
8,771 
10,024 
11,277 
6.0 
25 
12.1 
89 
22 
1,255 
2, 509 
3, 764 
5,019 
6, 273 
7,528 
8, 782 
10, 037 
11,292 
6.1 
26 
12.2 
90 
23 
1,256 
2,513 
3, 769 
5, 025 
6, 281 
7, 537 
8,794 
10, 050 
11,306 
6.3 
27 
12.3 
91 
24 
1,258 
2, 516 
3,774 
5, 032 
6, 2X9 
7,547 
8,805 
10, 063 
11, 321 
6.4 
28 
12.4 
93 
25 
1,260 
2,519 
3,779 
5,038 
6, 297 
7, 557 
8, 816 
10,076 
11,336 
6.5 
29 
12.5 
94 
26 
1,261 
2,522 
3,783 
5,044 
6, 306 
7, 567 
8, 828 
10,089 
11,350 
6.7 
30 
12.6 
96 
27 
1, 263 
2, 525 
3,788 
5, 051 
6,314 
7,576 
8,839 
10, 102 
11,365 
6.8 
31 
12.7 
97 
28 
1, 264 
2, 529 
3,793 
5,057 
6, 322 
7,586 
8,851 
10,115 
11,379 
6.9 
32 
12.8 
99 
29 
1, 266 
2,532 
3,798 
5,064 
6, 330 
7,596 
8,862 
10, 128 
11,394 
7.0 
33 
12.9 
100 
30 
1,268 
2,535 
3,803 
5,070 
6,338 
7,606 
8,873 
10,141 
11,409 
7.2 
34 
13.0 
102 
31 
1,269 
2, 538 
3,808 
5,077 
6, 346 
7,615 
8,885 
10, 154 
11,423 
7.3 
35 
13.1 
103 
32 
1, 271 
2,542 
3,813 
5,083 
6,354 
7, 625 
8,896 
10, 167 
11,438 
7.4 
36 
13.2 
105 
33 
1,273 
2, 545 
3,817 
5,090 
6,362 
7, 635 
8,907 
10, 180 
11, 452 
7.5 
37 
13.3 
106 
34 
1,274 
2,548 
3, 822 
5,096 
6,371 
7, 645 
8,919 
10, 193 
11,467 
7.6 
38 
13.4 
108 
35 
1,276 
2, 551 
3,827 
5, 103 
6,379 
7, 654 
8, 930 
10, 206 
11,482 
7.8 
39 
13.5 
109 
36 
1,277 
2, 555 
3, 832 
5, 109 
6,387 
7,664 
8, 942 
10, 219 
11,496 
7.9 
40 
13.6 
111 
37 
1,279 
2, 558 
3,837 
5,116 
6, 395 
7,674 
8,953 
10, 232 
11,511 
8.0 
41 
13.7 
112 
38 
1,281 
2, 561 
3, 842 
5, 122 
6,403 
7,684 
8,964 
10, 245 
11,526 
8.1 
42 
13.8 
114 
39 
1,282 
2,565 
3,847 
5,129 
6,411 
7,693 
8,976 
10, 258 
11,540 
8.2 
43 
13.9 
115 
40 
1,284 
2,568 
3, 852 
5,135 
6,419 
7,703 
8,987 
10, 271 
11,555 
8.3 
44 
14.0 
117 
41 
1,286 
2,571 
3,857 
5, 142 
6,427 
7,713 
8,999 
10, 284 
11,569 
8.4 
45 
14.1 
119 
42 
1,287 
2, 574 
3,861 
5, 149 
6,436 
7,723 
9,010 
10, 297 
11,584 
8.5 
46 
14.2 
120 
43 
1,289 
2,578 
3,866 
5,155 
6, 444 
7, 732 
9, 021 
10,310 
11,599 
8.6 
47 
14.3 
122 
44 
1,290 
2, 581 
3,871 
5, 162 
6,452 
7,742 
9,033 
10,323 
11,613 
8.7 
48 
14.4 
124 
45 
1, 292 
2,584 
3,876 
5,168 
6,460 
7, 752 
9,044 
10, 336 
11,628 
8.8 
49 
14.5 
125 
46 
1,294 
2, 587 
3,881 
5, 175 
6,468 
7, 762 
9, 055 
10, 349 
11,643 
8.9 
50 
14.6 
127 
47 
1, 295 
2,591 
3, 886 
5, 181 
6,476 
7,771 
9, 067 
10, 362 
11,657 
9.0 
51 
14.7 
129 
48 
1,297 
2,594 
3,891 
5,188 
6,484 
7,781 
9, 078 
10, 375 
11,672 
9.1 
52 
14.8 
130 
49 
1,299 
2,597 
3,896 
5,194 
6,493 
7,791 
9,090 
10, 388 
11,687 
9.2 
53 
14.9 
132 
60 
1,300 
2,600 
3.900 
5,201 
6,501 
7,801 
9,101 
10,401 
11,701 
9.3 
54 
15.0 
134 
51 
1,302 
2, 604 
3,905 
5,207 
6, 509 
7,811 
9,112 
10, 414 
11,716 
9.4 
55 
15.1 
135 
52 
1,303 
2,607 
3,910 
5, 214 
6, 517 
7,820 
9, 124 
10, 427 
11,731 
9.5 
56 
15.2 
137 
53 
1, 305 
2, 610 
3, 915 
5, 220 
6, 525 
7,830 
9, 135 
10,440 
11, 745 
9.6 
58 
15.3 
139 
54 
1,307 
2, 613 
3,920 
5,227 
6, 533 
7,840 
9,147 
10,453 
11,760 
9.7 
59 
15.4 
141 
55 
1,308 
2, 617 
3, 925 
5, 233 
6, 541 
7, 850 
9, 158 
10, 466 
11,775 
9.8 
60 
15.5 
142 
56 
1,310 
2, 620 
3,930 
5,240 
6,550 
7, 859 
9, 170 
10, 479 
11,789 
9.9 
61 
15.6 
144 
57 
1,312 
2,623 
3,935 
5,246 
6, 558 
7,869 
9,181 
10, 492 
11,804 
10.0 
62 
15.7 
146 
58 
1,313 
2, 626 
3,940 
5,253 
6, 566 
7,879 
9, 192 
10, 506 
11,819 
10.1 
63 
15.8 
148 
59 
1,315 
2, 630 
3,944 
5, 259 
6,574 
7,889 
9,204 
10, 519 
11, 833 
15.9 
16.0 
150 
151 
60 
1,316 
2,633 
3,949 
5,266 
6,582 
7,899 
9,215 
10, 532 
11, 848 
a For all distances under 1.6 miles the correction may be taken as + 5 feet. 
is assumed 4.5 feet. 
Height of instrument 
Bull. 21tt— 03- 
-17 
