Gannett] GEOGRAPHIC TABLES AND FORMULAS. 245 
Table 24. — For obtaining differences of altitude for any minute, etc. — Continued. 
1°. 
Corrections 
for curva- 
1 
2 
3 
4 
5 
(i 
7 
8 
9 
ture, refraction 
, and 
height of instruments 

92.2 
184.3 
276 
369 
461 
553 
645 
737 
829 
Miles. 
Feet. 
Miles. 
Feet. 
1 
93.7 
187.4 
281 
375 
468 
562 
656 
750 
843 
16.1 
153 
22.1 
285 
2 
95.2 
190. 5 
286 
381 
476 
571 
667 
762 
857 
16.2 
155 
22. 2 
287 
3 
96.8 
193.5 
290 
387 
484 
581 
677 
774 
871 
16.3 
157 
22. 3 
290 
4 
98.3 
196.6 
295 
393 
492 
590 
688 
786 
885 
16.4 
159 
22.4 
293 
5 
99.8 
199. 7 
300 
399 
499 
599 
699 
799 
899 
16.5 
161 
22.5 
295 
6 
101.4 
202. 8 
304 
406 
507 
608 
710 
811 
912 
16.6 
163 
22.6 
298 
7 
102. 9 
205. 8 
309 
412 
515 
618 
720 
823 
926 
16.7 
165 
22.7 
300 
8 
104.4 
208. 9 
313 
418 
522 
627 
731 
836 
940 
16.8 
167 
22.8 
303 
9 
106.0 
212.0 
318 
424 
530 
636 
742 
848 
954 
16.9 
168 
22.9 
306 
•10 
107.5 
215.1 
323 
430 
538 
645 
753 
860 
968 
17.0 
170 
23. 
308 
11 
109.1 
218. 1 
327 
436 
545 
654 
763 
873 
982 
17.1 
172 
23.1 
311 
12 
110.6 
221.2 
332 
442 
553 
664 
774 
885 
995 
17.2 
174 
23.2 
313 
13 
112. 1 
224. 3 
336 
449 
561 
673 
785 
897 
1,009 
17.3 
176 
23.3 
316 
14 
113.7 
227.3 
341 
455 
568 
682 
796 
909 
1,023 
17.4 
178 
23.4 
319 
15 
115.2 
230. 4 
346 
461 
576 
691 
sue, 
922 
1,037 
17.5 
180 
23. 5 
321 
16 
116.7 
233. 5 
350 
467 
584 
700 
817 
934 
1,051 
17.6 
182 
23.6 
324 
17 
118.3 
236. 6 
355 
473 
591 
710 
828 
946 
1, 065 
17.7 
184 
23.7 
327 
18 
119.8 
239.6 
359 
479 
599 
719 
839 
959 
1,078 
17.8 
186 
23.8 
330 
19 
121.4 
242.7 
364 
485 
607 
728 
849 
971 
1,092 
17.9 
188 
23.9 
332 
20 
122. 9 
245.8 
369 
492 
614 
737 
860 
983 
1,106 
18.0 
190 
24.0 
335 
21 
121.4 
248. 9 
373 
498 
622 
747 
871 
995 
1,120 
18.1 
193 
24.1 
338 
22 
126. 
251.9 
378 
504 
630 
756 
882 
1,008 
1,134 
18.2 
195 
24.2 
341 
23 
127.5 
255.0 
383 
510 
638 
765 
893 
1 , 020 
1,148 
18.3 
197 
24.3 
343 
24 
129.0 
258. 1 
387 
516 
615 
774 
903 
1,032 
1,161 
18.4 
199 
24.4 
346 
25 
130. 6 
261.2 
392 
522 
653 
783 
914 
1, 045 
1,175 
18.5 
201 
24.5 
349 
26 
132. 1 
264. 2 
396 
528 
661 
793 
925 
1,057 
1,189 
18.6 
203 
24.6 
352 
27 
133. 6 
267.3 
401 
535 
668 
802 
936 
1,069 
1,203 
18.7 
205 
24.7 
355 
28 
135.2 
270.4 
406 
541 
676 
811 
946 
1,082 
1, 217 
18.8 
207 
24.8 
358 
29 
136.7 
273.5 
410 
547 
684 
820 
957 
1,094 
1,231 
18.9 
210 
24.9 
360 
30 
138.3 
276. 5 
415 
553 
691 
830 
968 
1, 106 
1,244 
19.0 
212 
25.0 
363 
31 
139.8 
279.6 
419 
559 
699 
839 
979 
1,118 
1,258 
19.1 
214 
25.1 
366 
32 
141.3 
282. 7 
424 
565 
707 
848 
989 
1,131 
1, 272 
19.2 
216 
25.2 
369 
33 
142. 9 
285. 7 
429 
571 
714 
857 
1,000 
1,143 
1 , 286 
19.3 
218 
25.3 
372 
34 
144.4 
2SS. S 
433 
578 
722 
866 
1,011 
1,155 
1,300 
19.4 
221 
25.4 
375 
35 
146.0 
291.9 
438 
584 
730 
876 
1,022 
1, 168 
1,314 
19.5 
223 
25.5 
378 
36 
147. 5 
295. 
442 
590 
737 
885 
1,032 
1,180 
1,327 
19.6 
225 
25.6 
381 
37 
149.0 
298. 
447 
596 
745 
894 
1,043 
1,192 
1,341 
19.7 
227 
25.7 
384 
38 
150. 6 
301.1 
452 
602 
753 
903 
1,054 
1.204 
1,355 
19.8 
230 
25.8 
387 
39 
152. 1 
304. 2 
456 
608 
760 
913 
1,065 
1,217 
1,369 
19.9 
232 
25.9 
390 
40 
153.6 
307.3 
461 
615 
768 
922 
1,075 
1,229 
1,383 
20.0 
234 
26.0 
393 
41 
155. 2 
310. 3 
466 
621 
776 
931 
1,086 
1,241 
1,397 
20.1 
236 
26.2 
399 
42 
156. 7 
313.4 
470 
427 
784 
940 
1,097 
1, 254 
1,410 
20.2 
239 
26.4 
405 
43 
158. 2 
316.5 
475 
633 
791 
949 
1,108 
1,266 
1,424 
20.3 
241 
26. 6 
411 
44 
159.8 
319.6 
479 
639 
799 
959 
1,118 
1,278 
1,438 
20.4 
243 
26.8 
417 
45 
161.3 
322. 6 
484 
645 
807 
968 
1,129 
1,291 
1, 452 
20.5 
246 
27.0 
423 
46 
162.9 
325. 7 
489 
651 
814 
977 
1,140 
1,303 
1,466 
20.6 
248 
27.2 
429 
47 
164.4 
328. 8 
493 
658 
822 
986 
1,151 
1,315 
1,480 
20.7 
250 
27.4 
435 
48 
165. 9 
331.9 
498 
664 
830 
996 
1, 162 
1,327 
1,493 
20.8 
253 
27.6 
442 
49 
167. 5 
334.9 
502 
670 
837 
1,005 
1, 172 
1,340 
1,5C7 
20.9 
255 
27.8 
448 
50 
169.0 
338.0 
507 
676 
845 
1,014 
1,183 
1,352 
1,521 
21.0 
258 
28.0 
455 
51 
170.6 
341.1 
512 
682 
853 
1,023 
1,194 
1,364 
1,535 
21.1 
260 
28.2 
461 
52 
172.1 
344. 2 
516 
688 
860 
1,032 
1, 205 
1,377 
1,549 
21.2 
262 
28.4 
467 
53 
173.6 
347.2 
521 
694 
868 
1,042 
1,215 
1,389 
1,563 
21.3 
265 
28.6 
474 
54 
175.2 
350. 3 
525 
701 
876 
1,051 
1,226 
1,401 
1,576 
21.4 
267 
28.8 
480 
55 
176. 7 
353. 4 
530 
707 
883 
1,060 
1,237 
1,414 
1,590 
21.5 
270 
29.0 
487 
56 
178. 2 
356. 5 
535 
713 
891 
1 , 069 
1 , 248 
1,426 
1,604 
21.6 
272 
29.2 
494 
57 
179.8 
359. 5 
539 
719 
899 
1,079 
1, 258 
1,438 
1,618 
21.7 
275 
29.4 
501 
58 
181.3 
362. 6 
544 
725 
907 
1,088 
1,269 
1,450 
1,632 
21.8 
277 
29.6 
507 
59 
182. 8 
365.7 
549 
731 
914 
1,097 
1,280 
1,465 
1,643 
21.9 
280 
29.8 
514 
60 
184.4 
368.8 
553 
738 
922 
1,106 
1,291 
1,475 
1, 659 
22.0 
282 
30.0 
521 
a For all distances under 1. 
is assumed 4.5 feet. 
miles the correction may be taken as +5 feet. Height of instrument 
