Table III.—Reduction of Barometer Reading to 32°.

Inches.
Temperature
°F
24.0 24.5 25.0 25.5 26.0 26.5 27.0 27.5 28.0 28.5 29.0 29.5 30.0 30.5 31.0
30-.003-.003-.003-.003-.003-.003-.003-.003-.003-.004-.004-.004-.004-.004-.004
31 .005 .005 .005 .005 .006 .006 .006 .006 .006 .006 .006 .006 .006 .007 .007
32 .007 .008 .008 .008 .008 .008 .008 .008 .009 .009 .009 .009 .009 .009 .009
33 .010 .010 .010 .010 .010 .010 .011 .011 .011 .011 .012 .012 .012 .012 .012
34 .012 .012 .012 .012 .013 .013 .013 .013 .014 .014 .014 .014 .015 .015 .015
35 .014 .014 .014 .015 .015 .015 .016 .016 .016 .016 .017 .017 .017 .018 .018
36 .016 .016 .017 .017 .017 .018 .018 .018 .019 .019 .019 .020 .020 .020 .021
37 .018 .019 .019 .019 .020 .020 .021 .021 .021 .022 .022 .022 .023 .023 .024
38 .020 .021 .021 .022 .022 .022 .023 .023 .024 .024 .025 .025 .026 .026 .026
39 .023 .023 .024 .024 .024 .025 .025 .026 .026 .027 .027 .028 .028 .029 .029
40 .025 .025 .026 .026 .027 .027 .028 .028 .029 .030 .030 .030 .031 .031 .032
41 .027 .027 .028 .029 .029 .030 .030 .031 .031 .032 .033 .033 .034 .034 .035
42 .029 .030 .030 .031 .032 .032 .033 .033 .034 .034 .035 .036 .036 .037 .038
43 .031 .032 .033 .033 .034 .035 .035 .036 .036 .037 .038 .038 .039 .040 .040
44 .033 .034 .035 .035 .036 .037 .038 .038 .039 .040 .040 .041 .042 .042 .043
45 .036 .037 .037 .038 .039 .039 .040 .041 .042 .042 .043 .044 .045 .045 .046
46 .038 .038 .039 .040 .041 .042 .043 .043 .044 .045 .046 .046 .047 .048 .049
47 .040 .041 .042 .042 .043 .044 .045 .046 .047 .048 .048 .049 .050 .051 .052
48 .042 .043 .044 .045 .046 .047 .047 .048 .049 .050 .051 .052 .053 .053 .054
49 .044 .045 .046 .047 .048 .049 .050 .051 .052 .052 .054 .054 .055 .056 .057
50 .046 .047 .048 .049 .050 .051 .052 .053 .054 .055 .056 .057 .058 .059 .060
51 .049 .050 .051 .052 .053 .054 .055 .056 .057 .058 .059 .060 .061 .062 .063
52 .051 .052 .053 .054 .055 .056 .057 .058 .059 .060 .061 .062 .064 .065 .066
53 .053 .054 .055 .056 .057 .058 .060 .061 .062 .063 .064 .065 .066 .067 .068
54 .055 .056 .057 .058 .060 .061 .062 .063 .064 .065 .067 .068 .069 .070 .071
55 .057 .058 .060 .061 .062 .063 .064 .065 .066 .068 .069 .070 .071 .073 .074
56 .060 .061 .062 .063 .064 .065 .067 .068 .069 .070 .072 .073 .074 .075 .077
57 .062 .063 .064 .065 .067 .068 .069 .070 .072 .073 .075 .076 .077 .078 .080
58 .064 .065 .066 .068 .069 .070 .071 .073 .074 .076 .077 .078 .080 .081 .082
59 .066 .068 .069 .070 .072 .073 .074 .075 .077 .078 .080 .081 .083 .084 .085
60 .068 .070 .071 .072 .074 .076 .077 .078 .079 .081 .082 .084 .085 .086 .088
61 .070 .072 .073 .074 .076 .077 .079 .080 .082 .083 .085 .086 .088 .089 .091
62 .073 .074 .076 .077 .079 .080 .082 .083 .085 .086 .088 .089 .091 .092 .094
63 .075 .076 .078 .079 .081 .082 .084 .085 .087 .088 .090 .091 .093 .095 .096
64 .077 .078 .080 .081 .083 .085 .086 .088 .090 .091 .093 .094 .096 .097 .099
65-.079-.080-.082-.084-.086-.087-.089-.090-.092-.093-.095-.097-.099-.100-.102

Table III.—Reduction of Barometer Reading to 32°.—Continued.

Inches.
°F 24.0 24.5 25.0 25.5 26.0 26.5 27.0 27.5 28.0 28.5 29.0 29.5 30.0 30.5 31.0
65-.079-.080-.082-.084-.086-.087-.089-.090-.092-.093-.095-.097-.099-.100-.102
66 .081 .083 .085 .086 .088 .089 .091 .093 .095 .096 .098 .099 .101 .103 .105
67 .083 .085 .087 .088 .090 .092 .094 .095 .097 .099 .101 .102 .104 .106 .108
68 .085 .087 .089 .090 .093 .094 .096 .098 .100 .101 .103 .105 .107 .108 .110
69 .088 .089 .091 .093 .095 .097 .099 .100 .102 .104 .106 .107 .110 .111 .113
70 .090 .092 .094 .096 .097 .099 .101 .103 .105 .106 .109 .110 .112 .114 .116
71 .092 .094 .096 .098 .100 .101 .103 .105 .107 .109 .111 .113 .115 .116 .119
72 .094 .096 .098 .100 .102 .104 .106 .108 .110 .112 .114 .116 .118 .120 .122
73 .096 .098 .100 .102 .104 .106 .108 .110 .112 .114 .116 .118 .120 .122 .124
74 .098 .100 .103 .105 .107 .109 .111 .113 .115 .117 .119 .121 .123 .125 .127
75 .101 .102 .105 .106 .109 .111 .113 .115 .117 .119 .122 .124 .126 .128 .130
76 .103 .104 .107 .109 .111 .113 .116 .118 .120 .122 .124 .126 .128 .130 .133
77 .105 .107 .109 .111 .114 .116 .118 .120 .122 .124 .127 .129 .131 .133 .136
78 .107 .109 .112 .113 .116 .118 .120 .122 .125 .127 .129 .131 .134 .136 .138
79 .109 .111 .114 .116 .118 .120 .123 .125 .127 .129 .132 .134 .137 .139 .141
80 .111 .113 .116 .118 .121 .123 .125 .127 .130 .132 .135 .137 .139 .141 .144
81 .114 .116 .118 .120 .123 .125 .128 .130 .132 .134 .137 .139 .142 .144 .147
82 .116 .118 .121 .122 .125 .128 .130 .132 .135 .137 .140 .142 .145 .147 .149
83 .118 .120 .123 .125 .128 .130 .133 .135 .138 .140 .142 .145 .147 .149 .152
84 .120 .122 .125 .127 .130 .132 .135 .138 .140 .142 .145 .147 .150 .152 .155
85 .122 .124 .127 .129 .132 .134 .137 .139 .143 .145 .148 .150 .153 .155 .158
86 .124 .126 .128 .130 .135 .137 .140 .143 .145 .148 .150 .153 .155 .158 .161
87 .126 .129 .132 .134 .137 .139 .142 .144 .148 .150 .153 .155 .158 .161 .163
88 .129 .131 .134 .137 .139 .142 .145 .147 .150 .152 .155 .158 .161 .163 .166
89 .131 .133 .136 .139 .142 .144 .147 .150 .153 .155 .158 .161 .164 .166 .169
90 .133 .136 .138 .141 .144 .147 .150 .153 .155 .157 .161 .164 .166 .169 .172
91 .135 .138 .141 .143 .146 .149 .152 .155 .158 .160 .163 .166 .169 .172 .175
92 .137 .140 .143 .146 .149 .152 .154 .157 .160 .163 .166 .169 .172 .175 .177
93 .139 .142 .145 .148 .151 .154 .157 .160 .163 .166 .168 .171 .174 .177 .180
94 .142 .145 .147 .150 .153 .156 .159 .162 .165 .168 .171 .174 .177 .180 .183
95 .144 .147 .150 .153 .156 .159 .162 .165 .168 .171 .174 .177 .180 .183 .186
96 .146 .149 .152 .155 .158 .161 .164 .167 .170 .173 .176 .179 .182 .185 .188
97 .148 .151 .154 .157 .160 .164 .167 .170 .173 .176 .179 .182 .185 .188 .191
98 .150 .153 .156 .160 .163 .166 .169 .172 .175 .178 .181 .185 .188 .191 .194
99 .152 .155 .159 .162 .165 .168 .171 .175 .178 .181 .184 .187 .190 .194 .197
100-.154-.157-.161-.164-.167-.171-.174-.177-.180-.184-.187-.190-.193-.197-.200

Table IV.—Table for Reducing Observations of the Barometer to
Sea Level, Correction Additive.

Height, in feet. Temperature of external air—degrees Fahrenheit.
-20° -10° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100°
10 .013 .013 .012 .012 .012 .012 .011 .011 .011 .011 .010 .010 .010
20 .026 .025 .025 .024 .023 .023 .023 .022 .022 .021 .021 .020 .020
30 .039 .038 .037 .036 .035 .034 .034 .033 .032 .032 .031 .030 .030
40 .052 .050 .049 .048 .047 .046 .045 .044 .043 .042 .041 .040 .040
50 .065 .063 .061 .060 .059 .058 .056 .055 .054 .053 .052 .051 .050
60 .077 .076 .074 .072 .070 .069 .068 .066 .065 .063 .062 .061 .059
70 .090 .088 .086 .084 .082 .081 .078 .077 .076 .074 .072 .071 .069
80 .103 .101 .098 .096 .094 .092 .090 .088 .086 .084 .082 .081 .079
90 .116 .113 .111 .108 .105 .104 .101 .099 .097 .095 .093 .091 .089
100 .129 .126 .123 .120 .117 .115 .112 .110 .108 .105 .103 .101 .099
110 .142 .139 .135 .132 .129 .126 .123 .121 .119 .116 .113 .111 .109
120 .155 .151 .148 .144 .140 .138 .134 .132 .129 .126 .124 .121 .119
130 .168 .164 .160 .156 .152 .149 .146 .143 .140 .137 .134 .131 .129
140 .181 .176 .172 .168 .164 .161 .157 .154 .151 .147 .144 .141 .139
150 .194 .189 .185 .180 .176 .172 .168 .165 .162 .158 .155 .152 .149
160 .206 .201 .197 .192 .187 .183 .179 .176 .172 .168 .165 .162 .158
170 .219 .214 .209 .204 .199 .195 .190 .187 .183 .179 .175 .172 .168
180 .232 .227 .222 .216 .211 .206 .202 .198 .194 .189 .185 .182 .178
190 .245 .239 .234 .228 .222 .218 .213 .209 .204 .200 .196 .192 .188
200 .258 .252 .246 .240 .234 .229 .224 .220 .215 .210 .206 .202 .198
210 .271 .264 .258 .252 .246 .240 .235 .231 .226 .221 .216 .212 .208
220 .284 .277 .270 .264 .257 .252 .246 .242 .236 .231 .227 .222 .218
230 .296 .289 .283 .276 .269 .263 .257 .253 .247 .242 .237 .232 .228
240 .309 .302 .295 .288 .281 .275 .269 .264 .258 .252 .248 .242 .238
250 .322 .314 .307 .300 .293 .286 .280 .275 .269 .263 .258 .253 .248
260 .335 .327 .319 .311 .304 .297 .291 .285 .279 .273 .268 .263 .257
270 .348 .339 .331 .323 .316 .309 .302 .296 .290 .284 .278 .273 .267
280 .360 .352 .344 .335 .328 .320 .314 .307 .301 .294 .288 .283 .277
290 .373 .364 .356 .347 .339 .332 .325 .318 .311 .305 .299 .293 .287
300 .386 .377 .368 .359 .351 .343 .336 .329 .322 .315 .309 .303 .297
310 .399 .389 .380 .371 .363 .354 .347 .340 .333 .326 .319 .313 .307
320 .412 .402 .392 .383 .374 .366 .358 .351 .343 .336 .329 .323 .317
330 .424 .414 .404 .395 .386 .377 .369 .362 .354 .347 .340 .333 .326
340 .437 .427 .416 .407 .397 .389 .380 .373 .365 .357 .350 .343 .336
350 .450 .439 .429 .419 .409 .400 .392 .384 .376 .368 .360 .353 .346
360 .463 .451 .441 .430 .421 .411 .403 .394 .386 .378 .370 .363 .356
370 .476 .464 .453 .442 .432 .423 .414 .405 .397 .389 .380 .373 .366
380 .488 .476 .465 .454 .444 .434 .425 .416 .408 .399 .391 .383 .375
390 .501 .489 .477 .466 .455 .446 .436 .427 .418 .410 .401 .393 .385
400 .514 .501 .489 .478 .467 .457 .447 .438 .429 .420 .411 .403 .395
410 .527 .513 .501 .490 .479 .468 .458 .449 .440 .430 .421 .413 .405
420 .539 .526 .513 .502 .490 .480 .469 .460 .450 .441 .431 .423 .415
430 .552 .538 .525 .513 .502 .491 .480 .470 .461 .451 .442 .433 .425
440 .565 .551 .537 .525 .513 .502 .491 .481 .471 .462 .452 .443 .434
450 .578 .563 .550 .537 .525 .513 .503 .492 .482 .472 .462 .453 .444
460 .590 .575 .562 .549 .537 .525 .514 .503 .493 .482 .472 .463 .454
470 .603 .588 .574 .561 .548 .536 .525 .514 .503 .493 .482 .473 .464
480 .616 .600 .586 .572 .560 .547 .536 .524 .514 .503 .493 .483 .474
490 .628 .613 .598 .584 .571 .559 .547 .535 .524 .514 .503 .493 .483
500 .641 .625 .610 .596 .583 .570 .558 .546 .535 .524 .513 .503 .493
510 .654 .637 .622 .608 .594 .581 .569 .557 .545 .534 .523 .513 .503
520 .666 .650 .634 .620 .606 .593 .580 .568 .556 .545 .533 .523 .513
530 .679 .662 .646 .631 .617 .604 .591 .578 .566 .555 .544 .533 .522
540 .691 .675 .658 .643 .629 .615 .602 .589 .577 .565 .554 .543 .532

Table IV.—For Reducing Observations of the Barometer to Sea
Level.—Continued.

Height, in feet. Temperature of external air—degrees Fahrenheit.
-20° -10° 10° 20° 30° 40° 50° 60° 70° 80° 90° 100°
550 .704 .687 .670 .655 .640 .626 .613 .600 .587 .575 .564 .553 .542
560 .717 .699 .683 .667 .652 .638 .624 .611 .598 .586 .574 .563 .552
570 .729 .712 .695 .679 .663 .649 .635 .622 .608 .596 .584 .573 .562
580 .742 .724 .707 .690 .675 .660 .646 .632 .619 .606 .595 .583 .571
590 .754 .737 .719 .702 .686 .672 .657 .643 .629 .617 .605 .593 .581
600 .767 .749 .731 .714 .698 .683 .668 .654 .640 .627 .615 .603 .591
610 .780 .761 .743 .726 .709 .694 .679 .665 .650 .637 .625 .613 .601
620 .792 .774 .755 .738 .721 .705 .690 .675 .661 .648 .635 .623 .611
630 .805 .786 .767 .749 .732 .717 .701 .686 .671 .658 .645 .633 .620
640 .817 .798 .779 .761 .744 .728 .712 .697 .682 .668 .655 .643 .630
650 .830 .811 .791 .773 .755 .739 .723 .708 .692 .679 .666 .653 .640
660 .843 .823 .803 .785 .767 .750 .734 .718 .703 .689 .676 .662 .650
670 .855 .835 .815 .797 .778 .761 .745 .729 .713 .699 .686 .672 .660
680 .868 .847 .827 .808 .790 .773 .756 .740 .724 .709 .696 .682 .669
690 .880 .860 .839 .820 .801 .784 .767 .750 .734 .720 .706 .692 .679
700 .893 .872 .851 .832 .813 .795 .778 .761 .745 .730 .716 .702 .689
710 .905 .884 .863 .844 .824 .806 .789 .772 .755 .740 .726 .712 .698
720 .918 .896 .875 .855 .836 .817 .800 .782 .766 .751 .736 .722 .708
730 .930 .909 .887 .867 .847 .829 .811 .793 .776 .761 .746 .732 .718
740 .943 .921 .899 .879 .859 .840 .822 .804 .787 .771 .756 .742 .728
750 .955 .933 .911 .891 .870 .851 .833 .815 .797 .782 .767 .752 .738
760 .968 .945 .922 .902 .881 .862 .843 .825 .808 .792 .777 .761 .747
770 .980 .957 .934 .914 .893 .873 .854 .836 .818 .802 .787 .771 .757
780 .993 .970 .946 .926 .904 .885 .865 .847 .829 .812 .797 .781 .767
7901.005 .982 .958 .937 .916 .896 .876 .857 .839 .823 .807 .791 .776
8001.018 .994 .970 .949 .927 .907 .887 .868 .850 .833 .817 .801 .786
8101.0301.006 .982 .961 .938 .918 .898 .878 .860 .843 .827 .811 .796
8201.0431.018 .994 .972 .950 .929 .909 .889 .871 .854 .937 .821 .805
8301.0551.0311.006 .984 .961 .940 .920 .900 .881 .864 .847 .831 .815
8401.0681.0431.018 .995 .973 .951 .931 .911 .892 .874 .857 .841 .825
8501.0801.0551.0301.007 .984 .962 .942 .922 .902 .885 .867 .851 .835
8601.0931.0671.0411.019 .995 .974 .952 .932 .913 .895 .877 .860 .844
8701.1051.0791.0531.0301.007 .985 .963 .943 .923 .905 .887 .870 .854
8801.1181.0921.0651.0421.018 .996 .974 .954 .934 .915 .897 .880 .864
8901.1301.1041.0771.0531.0301.007 .985 .904 .944 .926 .907 .890 .873
9001.1431.1161.0891.0651.0411.018 .996 .975 .955 .936 .917 .900 .883
9101.1551.1281.1011.0771.0521.0291.007 .986 .965 .946 .927 .910 .893
9201.1681.1401.1131.0881.0641.0401.018 .996 .976 .956 .937 .920 .902
9301.1801.1521.1251.1001.0751.0511.0291.007 .986 .967 .947 .929 .912
9401.1931.1641.1371.1111.0861.0621.0401.017 .997 .977 .957 .939 .921
9501.2051.1771.1491.1231.0981.0741.0511.0281.007 .987 .967 .949 .931
9601.2171.1891.1601.1351.1091.0851.0611.0391.017 .997 .977 .959 .941
9701.2301.2011.1721.1461.1201.0961.0721.0491.0281.007 .987 .969 .950
9801.2421.2131.1841.1581.1311.1071.0831.0601.0381.018 .997 .978 .960
9901.2551.2251.1961.1691.1431.1181.0941.0701.0491.0281.007 .988 .969
10001.2671.2371.2081.1811.1541.1291.1051.0811.0591.0381.017 .998 .979
10101.2791.2491.2201.1921.1651.1401.1161.0921.0691.0481.0271.008 .989
10201.2921.2611.2321.2041.1771.1511.1271.1021.0801.0581.0371.018 .998
10301.3041.2731.2431.2151.1881.1621.1371.1131.0901.0691.0471.0271.008
10401.3171.2851.2551.2271.1991.1731.1481.1231.1011.0791.0571.0371.017
10501.3291.2981.2671.2381.2111.1841.1591.1341.1111.0891.0671.0471.027
10601.3411.3101.2791.2501.2221.1951.1701.1451.1211.0991.0771.0571.037
10701.3541.3221.2911.2611.2331.2061.1811.1551.1321.1091.0871.0671.046
10801.3661.3341.3021.2731.2441.2171.1911.1661.1421.1201.0971.0761.056
10901.3791.3461.3141.2841.2561.2281.2021.1761.1531.1301.1071.0861.065