BAROMETRIC DETERMINATION OF HEIGHTS.

FIELD SEASON, 1883.

Party No. 1.

Division of Fort Wingate, N. M.

H. M. Wilson, Computer.

Observations recorded in books No. 306 and No. 309.

GUYOT'S BAROMETRIC TABLES.

383

argument for D(H) the height of the moving barometer. If the new station be lower than the base, the difference between D'(h) and D(H) is given a negative sign. The corrections D., D, etc., are added to the first approximate result regardless of its signs, attention being paid to the signs of the corrections, which are generally positive.

The correction D,, is the product of the first approximation into the factor found in Table XVIII, the argument for which is tť or the sum of temperatures of the detached thermometers of the two stations. When the humidity correction is used the relative humidities are first found from Lee's Tables, the arguments being the difference between the wet and dry bulbs and the reading of the wet bulb, though this correction scarce affects the result appreciably and may be omitted.

173. Guyot's Barometric Tables.-Table XVII gives in English feet the value of log H or h X 60158.6 for each hundredth of an inch from 12 to 31 inches of barometric pressure. The additional thousandths are obtained in a separate column.

Table XVIII gives the correction 2.343 feet X (T- τ') for the different temperatures of the barometers at the two stations; and as that at the upper station is generally lower, τ 7' is generally positive and the correction negative. This correction becomes positive only when the temperature of the upper barometer is higher.

Table XIX shows the correction D'

2 + 52252
20886860

to be

applied to the approximate altitude for the decrease of gravity on a vertical acting on the density of the mercurial column. It is always added.

Table XX furnishes the small correction

h 10443430

for

the decrease of gravity on a vertical acting on the density of

the air. This correction is always added.

TABLE XVII.

REDUCTION OF BAROMETRIC READINGS TO FEET.

D= 60158.58 X log H or h. Argument: The observed height of the barometer at either station. (Extracted from Smithsonian Miscellaneous Contributions.)

5001.8 5023.4 5044.9 5066.4

5087.9

5109.4

5130.9

5152.4

5173.8

12. I

12.2

5195.2

12.3

5408.5

5216.6 5238.0 5259.4
5280.7
5429.8 5452.0 5472.2 5493.4
5620. I 5641.2 5662.2 5683.2 5704-3
5829.9 5850.8 5871.7 5892.6 5913.4 5934.2 5955.0
6038.1 6058.8 6079.6 6100.2 6120.9 6141.6 6162.2
6244.6 6265.2 6285.8 6306.3 6326.8 6347.3 6367.8
6449.6 6470.0 6490.4 6510.8 6531.1 6551.5 6571.8
6652.9 6673.2 6693.4 6713.6 6733.8 6754.0 6774.I

5302. I

5323.4

5344.7 5367.0

5387.2

12.2

TABLE XVII.-REDUCTION OF BAROMETRIC READINGS TO FEET.

Hundredths of an inch.

GUYOT'S BAROMETRIC TABLES.

Barom-
eter in

Eng.
inches.

Barom

eter in
Eng.
inches.

8865.4

14. I

9032.4 9050.8]

14.2

9216.6 9234.9

3

8976.8 8995-4 9013.9
9161.4 9179.8| 9198.2
9344-7 9363.0 9381.3 9399.5 9417.7 9436.0
9526.8 9545.0 9563.1 9581.2 9599.3 9617.4
9707.6
9725.7 9743-7 9761.7 9779.6 9797.6
9815.6 9833.5 9851.4 9869.3 9 17.0
9887.2 9905. I 9923.0 9940.9 9958.7 9976.5 9994.4 10012.2 10030.0 10047.8
10065.5 10083.3 10101.1 10118.8 10136.6 10154.3 10172.0 10189.7 10207.4 10225.1
10242.7 10260.4 10278.0 10295.7 10313.3 10330 9 10348.5 10366.1 10383.6 10401.2
10418.7 10436.3 10453.8 10471.3 10488.8 10506.3 10523.7 10541.2 10558.6 10576.0
10593.4 10610.8 10628.2 10645.6 10662.9 10680.3 10697.6 10715.0 10732.3 10749.6
10766.9 10784.1 10801.5 10818.7 10836.0 10853.2 10870.5 10887.7 10904.9 10922.1 4 6.8
10939.3 10956.5 10973.6 10990.8 11008.0 11025.1 11042.2 11059.3 11076.4 11093.5 5
8.5
11110.6 11127.7 11144.7 11161.8 11178.8 11195.8 11212.8 11229.8 11246.8 11263.8 6 10.2
11280.8 11297.8 11314.7 11331.6 11348.6 11365.5 11382.4 11399.3 11416.2 11433.0 7 11.9
11449.9 11466.7 11483.6 11500.4 11517.2 11534.0 11550.8 11567.6 11584.4 11601.1 8 13.6
11617.9 11634.6 11651.4 11668.1 11684.8 11701.5 11718.2 11734.9 11751.6 11768.2 9 15.3
11784.9 11801.5 11818.2 11834.8 11851.4 11868.0 11884.6 11901.1 11917.7 11934-3
11950.8 11967.3 11983.0 12000.4 12016.9 12033.3 12049.8 12066.3 12082.7 12099.2
12115.6 12132.0 12148.4 12164.8 12181.2 12197.6 12214.0 12230.4 12246.7 12263.1
12279.6 12295.9 12312.2 12328.5 12344.8 12361.1 12377.4 12393.6 12409.9 12426.1
12442.4 12458.6 12474.8 12491.0 12507.2 12523.4 12539.6 12555.7 12571.9 12588.0
12604.2 12620.3 12636.4 12652.5 12668.6 12684.7 12700.8 12716.8 12732.9 12748.9
12765.0 12781.0 12797.0 12813.0 12829.0 12845.0 12861.0 12876.9 12892.9 12908.8,
12924.8 12940.7 12956.6 12972.5 12988.4 13004.3 13020.2 13036.0 13051.9 13067.7

8884.0

8902.6

8921.2

8939.7

8958.3

9454.2 9472.3 9490.5 9508.7 7 13.2 9635-5 9653.5 9671.6 9689.6

45678

7.5

14.0

14. I

II.3

34567

TABLE XVII.-REDUCTION OF BAROMETRIC READINGS TO FEET.

16.5

Eng.
inches.

16.6

16.7

16.8

17.1

17.2
17.3
17.4

17.5
17.6

Eng. ft. Eng. ft. Eng. ft.
Eng. ft. Eng. ft. Eng. ft. Eng. ft.
Eng. ft. Eng. ft.
13083.6 13099.4 13115.2 13131.0 13146.8 13162.6 13178.0 13194.2 13210.0 13225.7
13241.5 13257.2 13272.9 13288.6 13304.3 13320.0 13335.7 13351.5 13367.1 13382.7
13398.4 13414.0 13429.6 13445.2 13460.8 13476.4 13492.0 13507.6 13523.2 13538.7
13554.3 13569.8 13585.4 13600.9 13616.4 13631.9 13647.4 13662.9 13678.4 13693.9
16.9
13709.4 13724.8 13740.3 13755.7 13771.1 13786.5 13801.9 13817.3 13832.7 13848.1
17.0 13863.5 13878.8 13894.2 13909.6 13924.9 13940.2 13955.6 13970.9 13986.2 14001.5
14016.8 14032.0 14047.3 14062.6 14077.8 14093.0 14108.3 14123.5 14138.7 14153.9
14169.1 14184.3 14199.4 14214.6 14229.8 14244.9 14260.1 14275.2 14290.3 14305.5
14320.6 14335.7 14350.8 14365.8 14380.9 14396.0 14411.0 14426.1 14441.1 14456.2
14471.2 14486.2 14501.2 14516.2 14531.2 14546.1 14561.1 14576.1 14591 0 14605.9
14620.9 14635.8 14650.7 14664.6 14680.5 14695.4 14710.3 14725.2 14740.1 14754.9
14769.8 14784.6 14799.4 14814.3 14829.1 14843.9 14858.7 14873.5 14888.2 14903.0
14917.8 14932.5 14947.3 14962.0 14976.8 14991.5 15006.2 15020.9 15035.6 15050.3
15065.0 15079.6 15094.3 15109.0 15123.6 15138.2 15152.9 15167.5 15122.1 15196.7
15211.3 15225.9 15240.5 15255.0 15269.6 15284.2 15298.7 15313.3 15327.8 15342.4
15356.8 15371.3 15385.8 15400.3 15414.8 15429.3 15443-7 15458.2 15472.7 15487.1
15501.5 15516.0 15530.4 15544.8 15559.2 15573.6 15588.0 15602.4 15616.8 15631.2
15645.5 15659.9 15674.2 15688.5 15702.9 15717.2 15731.5 15745.8 15760.1 15774-4
15788.6 15802.9 15817.2 15831.4 15845.7 15859.9 15874.2 15888.4 15902.6 15916.8
15931.0 15945.2 15959.4 15973.6 15987.8 16001.9 16016.1 16030.2 16044.4 16058.5
18.5 16072.6 16086.8 16100.9 16115.0 16129.1 16143.2 16157.3 16171.3 16185.4 16199.5
18.6 16213.5 16227.6 16241.6 16255.6 16269.7 16283.7 16297.7 16311.7 16325.7 16339.6
18.7 16353.5 16367.5 16381.5 16395.4 16409.4 16423.3 16437.2 16451.2 16465.1 16479.0
16492.9 16506.8 16520.7 16534.6 16548.5 16562.3 16576.2 16590.0 16603.9 16617.8
16631.5 16645.4 16659.2 16673.0 16686.8 16700.6 16714.4 16728.1 16741.9 16755.7

17.7

17.8

17.9

18.0
18.1

18.2

18.3

18.4

18.8 18.9

Thousandths of an inch.

.05

.06

.07

.08

.09

Barom

eter in
Eng.
inches.

Eng. ft.