T A B L p] S FOK OBTAINING THE TEMPERATURE OF THE DEW-POINT, RELATIVE HUMIDITY. AND VAPOR PRESSURE. PREPARED FOR USE UNITED STATES SIGNAL SERVICE. WASHINGTON CITY: SIGNAL OFFICE, 1889. TABLES FOR OBTAINING THE TEMPERATURE OF THE DEW-POINT, RELATIVE HUMIDITY, AND VAPOR PRESSURE. PREPARED FOR USE IN THE UNITED STATES SIGNAL SERVICE. * <5Awx\ c*\,c*^ WASHINGTON CITY : SIGNAL OFFICE, 1889. UNITED STATES SIGNAL SERVICE DEW-POINT, RELATIVE HUMIDITY, AND VAPOR PRESSURE TABLES. The following tables are published for the use of the observers of the Signal Service and other co-operating observers, to be used on and after July 1, 1889. Use of the tables. The psychrometric formula below, and the tables based upon it, are for use in obtaining the dew-point and relative humidity from readings of the dry and wet thermometers. These tables are strictly applicable to roof shelters and the whirled psychrometer, but may be used with- out much error for all shelters fairly well ventilated. The formula (Ferrel's) is as follows: p = p' 0.000367 P (t t') fl + " In which > p = vapor pressure of saturation at the dew-point temperature. p' vapor pressure of saturation at the wet-bulb temperature. P =. barometric pressure. t =. dry thermometer. t f == wet thermometer. Having given t and t r , the values of dew-point and relative humidity at 29.4 inches pressure (chosen because it is the mean pressure for all stations) may be immediately taken from the tables. Example. Given t =. 60; t V = 12. Entering the table on page 6, with t = 60 and t t' = 12, we find the dew-point = 35 ; and on page 16 the relative humidity 39 per cent. There is a small correction to be applied to these values, if great refinement is required, at pressures greater or less than 29.4 inches. This may be obtained by the use of the table on page 24 in connection with the vapor pressure given on page 23. Having found the dew- point, determine the vapor pressure corresponding to that dew-point. Then in the table on page 24, with the air pressure and t $', find the correction to this vapor pressure. Find the dew-point correspond- ing to this corrected vapor pressure from the table on page 23, and with the corrected dew-point find the proper relative humidity. Example. Given P =. 27 inches ; t 60 and V = 48. The table, as above, gives the dew-point 35. The vapor pressure corresponding is .203 of an inch ; correction from the table on page 24 for P=: 27 inches and t t' = 12 is -f- .010. Vapor pressure corrected , =. .213 ; corresponding dew-point, = 36. Each page of the relative humidity table is ten pages ahead of its corresponding page of dew-points. The dew-point 36, corrected for 368376 barometric pressure, on page 6, is ona line lower than the dew- point originally found. The corresponding line, on page 16, under the 12 heading, gives the corrected relative humidity 40 per cent. For an observation falling outside the limits of the table, the nearest values to the observations in the tables will be taken as the dew-point and relative humidity. For example, for a reading of the dry ther- mometer of 44 and a difference of the dry and wet thermometers of 15.0, there being no values given in the table for 15.0 those for a difference of 14. 5 will be taken. The dew-point and relative humidity will therefore be recorded as 42 and 2 per cent. The values of the vapor pressures down to 58 Fahrenheit used in computing these tables were obtained by means of Broch's formula, which is based on Regnault's observations. The lowest temperature at which Kegnault observed vapor pressure was about 27. In the series of observations from which the constants for the psy- chrometric formula given above was derived, the lowest dry thermome- ter temperature observed was 6. 4 Fahrenheit. A. W. GREELY, Chief Signal Officer. SIGNAL OFFICE, WASHINGTON CITY, July 1, 1889. Temperature of the dew point, in degrees Fahrenheit. K> "** Difference between the dry and wet thermometers (t t'). 1 5 00.2 o-4 ! o.6 o.8 10.0 10.2 .".4 '' 6 10.8 2.0 2. 2 2-4 2. 6 | 40 49 |j 40 47 g (t-f) 39 ig -46 "* t>* -38 -37 44 -56 i O. I 0.2 37' -36 43 53 ^_ -36 35 41 -50 _ eg -35 34 33 32 -31 40 39 37 -36 48 -46 44 42 57 i -53 49 48 47 -46 -56 54 53 51 34 33 32 30 29 28 27 26 35 -4i 34 39 -32 -37 31 36 30 35 -50 -48 45 43 41 -58 53 50 45 1 50 58 44 | 48 I '55 43 47 53 42 46 i 52 41 45 51 30 -29 28 27 -26 24 28 O't- 33 -37 44 -56 24 23 26 30 35 41 j 23 22 -25 29 33 -39 -48 22 21 24 27 32 37 -44 21 2O 23 26 30 35 41 2O 19 22 25 -29 33 39 47 19 18 21 24 27 3i 37 44 18 17 20 22 26 34 40 49 17 16 18 21 24 28 32 -38 45 16 15 17 2O 23 26 3 35 41 52 j 15 14 16 19 22 -25 -28 -33 -38 47 H 13 -la -'4 IS 20 - *Q 23 21 26 24 3 28 -36 33 42 39 47 13 12 ii 13 15 18 2O 26 30 -36 43 II 10 12 14 -16 19 22 25 -28 33 38 47 10 Q II -13 15 17 2O 23 26 35 42 9 8 IO 12 14 16 19 21 25 28 32 38 ! -47 8 7 9 10 12 15 17 20 23 26 29 35 | 4i , 7 6 8 9 II 13 15 18 21 24 -27 "-3i 37 : 45 i 6 5 7 Q IO 12 14 16 19 22 -25 29 33 39 49 _ 5 3 5 4 -I 9 8 II II -15 13 17 16 20 18 23 21 26 24 3 i 35 43 27 ; 32 38 4 3 2 3 5 6 8 10 12 *4 16 19 22 25 : -29 -34 2 ~ J 2 4 5 ~ 7 9 10 12 15 ~ X 7 2O 23 26 30 I O I I O 3 2 4 3 6 4 -I = 1 II 13 ii 15 13 18 16 i 21 i 24 18 ; 2i 28 25. O I 2 4- i 2 3 5 6 8 IO 12 14 16 i 19 22 2 3 2 + I I 3 5 6 8 IO 12 14 17 20 3 4 3 2 i 2 4 5 - 7 8 10 13 15 i 17 4 5 4 3 + 2 o I 2 4 5 7 9 ii 13 15 5 6 5 4 3 + 2 O I 2 4 5 7 9 | ii 13 6 7 6 5 4 3 4- i I 2 4 6 7 - 9 II 7 8 7 6 5 4 3 + 2 ' O I 3 4 -6 | -7 9 8 9 8 7 6 5 4 3 + 2 O i 3 6 8 9 10 9 8 7 6 5 4 3 4- 2 ! 3 4 6 10 ii 10 9 8 7 6 5 4 3 4-2 i 2 4 II . 12 ii 10 9 8 7 6 5 4 3 + 2 I 3 12 13 12 ii IO 9 9 8 7 5 4 3 4-2+1 i 13 14 13 12 12 II 10 9 8 7 6 5 3 2 14 15 14 13 13 12 ii 10 9 8 7 6 5 4 4 2 15 16 15 14 14 13 12 ii IO 9 8 7 6 5 3 16 17 16 16 15 14 13 12 ii 10 9 8 7 6 5 17 18 17 17 16 15 14 14 '3 12 ii IO 9 8 6 18 19 18 18 17 16 15 IS H 13 12 ii 10 9 ! 8 19 20 19 19 18 17 16 16 15 14 13 12 12 j IO 1 9 20 t 0.2 o.4 o.6 o.S I'.O ..., -.4 10.6 ,.8 2.0 2. 2 2. 4 2. 6 t Temperature of the dew point, in degrees Fahrenheit. to +* Difference between the dry and wet thermometers (tf ). 1 Q 2. 6 2. 8 3-o 3. 2 3- 4 3. 6 3. 8 4 .o 4.2 40.4 5 2 34 39 49 2 I -30 35 42 I 27 31 -37 45 O I 25 28 32 39 -48 I 2 22 25 29 34 40 54 2 3 20 23 25 30 35 42 54 3 4 17 20 24 26 30 -36 44 4 5 6 7 15 13 II 18 16 13 21 18 16 25 22 19 27 23 22 27 24 37 -S -46 -38 33 -48 39 49 6 5 7 8 9 ii -13 16 19 22 24 28 33 40 8 9 8 9 ii 14 16 -19 21 24 28 33 9 10 6 - 7 i - 9 12 14 16 19 21 24 -28 10 ii 4 6 7 10 12 14 16 19 21 24 ii 12 3 4 i - 6 8 9 II 14 -16 18 21 12 13 i 2 4 6 9 ii -13 16 19 13 14 o 12 4 5 7 9 ii 13 16 H 15 4-24-1 o 2 - 3 - 5 7 9 ii 13 15 16 3 2J4-I O 2 - 3 5 6 - 8 10 16 17 5 4 3 4- 2 O i 3 -~ 4 6 8 17 18 6 5 4 3 4-2 4- 1 i 2 4 6 18 19 8 7 6 5 4 2 4-i O 2 4 19 20 9 8 ! 7 6 5 4 3 + I O i 20 i 2 o.6 2 o.8 3 o. 3-2 3-4 3 o. 6 3. 8 4.0 4.2 4- 4 t e 4. 6 4. 8 5 o. 5-2 5-4 5-6 5. 8 6.o 60.2 60.4 t 8 50 8 9 40 -52 9 10 34 41 52 10 ii 29 34 41 -53 ii 12 24 -29 -34 41 53 12 13 20 24 28 34 40 52 13 14 17 20 24 28 -32 40 -51 14 15 14 17 20 23 27 33 39 50 I5 16 12 14 16 19 22 27 32 38 49 16 17 10 II -13 16 --18 22 26 3i -38 47 17 18 8 10 ii 13 15 18 21 30 -36 18 19 5 7 9 10 12 15 17 21 -25 29 19 20 3 -5 6 9 9 12 14 17 20 -23 20 t 4 .6 4. 8 5-o 5. 2 5- 4 5-6 5 0.8 6.o 6. 2 60.4 t Temperature of Ike dew point, in degrees Fahrenheit. ^ o> A Difference between the dry and wet thermometers (t /' ). 10 >J | > >. 5 o-5 i.o i.5 2.0 2. 5 3-o 3-5 4-o 4- 5 50.0 5- 5 6.o s 20 18 16 14 12 9 7 4 i - 3 - 7 -13 -17 20 21 19 18 16 H ii 9 6 3 i 4 10 15 21 22 20 19 17 15 12 10 7 5 + i 2 7 12 22 23 21 20 18 16 14 12 9 6 3 O 5 9 23 24 22 21 19 17 15 13 10 8 5 + 2 2 6 24 25 23 22 20 18 16 14 12 10 7 4 3 25 26 24 23 21 20 18 16 13 ii 8 6 ~t~ 2 i 26 27 2 5 24 22 21 19 17 15 13 10 8 4 -4- i 27 28 26 25 23 22 20 18 16 14 ii 9 6 3 28 29 2 7 26 24 23 21 20 18 16 13 ii 8 5 2 9 & 28 27 25 24 22 21 19 17 I5 13 10 7 3 31 29 28 26 25 23 22 20 19 16 H ii 9 31 32 30 2 9 28 27 25 23 21 20 18 16 13 ii 32 33 31 30 29 28 26 25 23 21 19 17 15 13 33 34 32 31 3 2 9 27 16 24 23 21 19 16 H 34 35 33 32 31 30 28 27 25 24 22 20 18 16 35 3P 35 34 32 31 29 28 26 25 23 22 20 18 36 37 36 35 33 32 30 29 27 26 24 23 21 19 37 3* 37 36 34 33 32 31 29 28 26 24 22 21 38 39 38 37 35 34 33 32 3 29 27 26 24 22 39 40 39 38 36 35 34 33 31 30 28 27 25 24 40 4 1 40 39 37 36 35 34 32 31 29 28 26 25 42 41 40 39 38 36 35 34 33 31 29 27 26 42 43 42 41 40 39 37 36 35 34 32 31 28 28 43 44 43 42 4i 40 38 37 36 35 33 32 30 29 44 M 44 45 43 44 42 43 42 40 39 40 38 36 37 34 36 33 35 31 33 32 i 47 46 45 44 43 42 41 40 39 37 36 34 33 47 48 47 46 45 44 43 42 41 40 38 37 36 35 48 49 48 47 46 45 44 43 42 41 39 38 37 36 49 50 49 48 47 46 45 44 43 42 4i 40 38 37 50 50 49 48 47 46 45 44 43 42 39 38 52 51 50 49 48 47 46 45 44 43 42 40 52 53 52 51 50 49 48 47 46 45 44 43 42 41 53 54 53 52 50 50 49 47 46 45 44 43 42 54 55 54 53 53 52 5I 50 49 48 47 46 44 43 55 56 57 54 55 54 53 54 52 53 52 50 49 50 48 49 % 45 47 44 46 57 58 57 56 56 55 54 53 52 50 49 48 47 58 59 58 57 57 56 55 54 53 52 51 50 49 48 , 59 60 59 58 58 57 56 55 54 53 52 5I 50 49 60 61 60 59 59 58 57 56 54 53 52 50 61 62 61 60 60 59 58 56 54 53 52 52 62 63 62 61 61 60 58 57 56 55 54 53 63 64 63 62 62 61 60 59 58 57 56 56 55 54 64 65 64 63 63 62 61 60 59 59 58 57 56 55 65 66 65 64 64 63 62 61 60 60 59 58 57 56 66 67 68 67 68 66 67 65 66 64 65 63 64 62 63 61 62 61 62 60 61 i 58 59 57 58 68 69 69 68 67 66 65 64 63 63 62 61 60 59 69 70 70 69 68 67 67 66 65 64 63 62 61 61 70 71 70 69 68 68 67 66 65 64 63 62 62 71 72 73 72 73 72 70 69 70 69 70 68 69 6? 66 67 66 1 64 72 73 74 74 73 72 71 70 69 68 67 67 66 65 74 75 75 74 73 72 72 7i 70 69 68 68 67 66 75 76 76 75 74 73 73 72 71 . 70 69 69 68 67 76 77 78 79 11 79 76 75 76 77 74 11 74 g 73 74 75 72 73 74 72 73 70 72 70 72 69 70 71 68 69 70 77 78 79 So 80 79 78 77 77 76 75 74 73 73 72 72 80 o. 5 10.0 .5 2.0 2. 5 3-o 3-5 4 .o 4- 5 5-o 5-5 6.o t Temperature of the dew point, in degrees Fahrenheit. a> Difference between the dry and wet thermometers (t t' ). iC & -K> "*-* g 6.o 6- 5 70.0 7- 5 80.0 8. 5 9.o 9-5 10. 100.5 11. u0. 5 12. Q 19 -32 59 19 20 19 26 41 20 21 15 21 32 21 22 12 T8 25 41 22 23 9 -15 20 31 59 23 24 6 12 16 25 40 24 25 3 8 14 22 30 55 25 26 27 i 5 3 10 - 7 17 13 -11 37 29 50 26 28 3 4 10 16 22 35 28 2 9 5 + 2 - 7 12 18 27 45 29 30 7 4 + i _ 3 8 14 20 32 30 31 9 6 3 + i 5 10 16 24 39 31 32 ii 8 5 2 2 - 7 12 18 28 52 32 33 13 10 7 4 4 8 14 21 34 33 34 14 ii 9 6 + 3 i 5 10 18 25 42 34 35 16 13 ii 8 5 + 2 2 - 7 -15 20 29 55 35 36 18 15 13 10 8 4 + I 3 8 15 21 35 36 37 19 17 15 12 10 7 4 5 10 17 25 43 37 38 21 19 14 12 9 6 + 3 i 6 12 29 38 39 22 20 18 16 14 ii 8 5 + 2 3 8 14 20 39 40 24 22 20 18 16 13 ii 7 4 o 4 10 16 40 41 25 23 22 19 17 15 13 10 7 + 3 5 ii 41 42 26 24 23 21 19 17 15 12 9 6 + 3 i 6 42 43 28 26 25 23 31 19 17 14 12 9 6 -f- 2 2 43 44 29 27 26 24 23 21 19 16 14 ii 8 5 + I 44 45 30 28 27 26 24 22 20 18 16 13 ii 7 4 45 46 32 30 2 9 27 26 24 22 20 18 15 13 10 7 46 47 33 31 3 29 27 25 24 22 20 ' 17 15 12 10 47 48 33 32 30 29 27 25 23 22 19 17 14 12 48 49 36 34 33 31 30 28 27 25 23 21 19 17 14 49 50 37 35 34 33 31 30 28 27 25 23 21 19 17 50 51 38 37 36 34 33 31 30 28 27 25 23 21 19 52 40 38 37 36 34 33 31 30 28 27 25 23 21 52 53 41 39 38 37 36 34 33 31 30 28 27 25 23 53 54 42 40 39 37 36 34 33 31 30 28 27 25 54 55 43 42 41 40 39 37 36 34 33 31 30 28 27 55 56 44 43 42 41 40 39 37 36 34 33 31 30 28 56 57 58 46 47 45 46 44 45 42 44 42 40 41 39 40 37 39 36 37 33 31 33 30 31 57 58 59 48 47 46 45 44 43 4i 40 39 38 36 35 33 59 60 49 48 47 46 45 44 43 41 40 39 38 36 35 60 61 50 49 48 47 46 45 44 43 42 39 38 36 61 62 52 51 50 49 48 47 45 44 43 42 39 38 62 63 53 52 51 50 49 48 47 45 44 43 42 39 63- 64 54 53 52 50 49 48 47 46 45 43 42 41 64 65 55 54 53 52 51 50 49 48 47 46 45 43 42 65 66 56 55 54 53 52 51 So 49 48 47 46 45 44 66 67 57 56 55 55 54 53 52 50 48 47 46 45 67 68 58 57 57 56 54 53 52 50 49 47 46 68 69 59 58 58 57 56 55 54 53 52 50 49 48 69 70 61 60 59 58 57 56 55 54 53 52 51 50 49 70 7 1 62 61 60 59 58 57 56 55- 55 54 53 52 7* 72 73 63 64 62 63 61 62 60 62 59 61 59 60 58 59 57. 58 56 57 55, 56 54 53 54 52 53 72 73 74 65 64 63 63 62 61 60 59 58 57 56 55 54 74 75 66 65 64 64 63 62 61 60 59 58 57 56 56 75 76 67 66 65 65 64 63 62 61 61 60 59 58 57 76 77 68 67 67 66 65 64 63 62 62 61 60 59 58 77 78 69 68 68 67 66 66 65 94 63 62 61 60 59 78 79 70 69 69 68 67 67 66 65 64 63 62 61 61 79 80 72 7i 70 69 68 68 67 66 65 64 63 62 62 80 t 6.o 6-5 7 o.o 7-5 8.o 80.5 9-o 9- 5 10. O o. 5 ,0.0 ' jO, c 120.0 t Temperature of the dew point, in degrees Fahrenheit. 7 o ,G Difference between the dry and wet thermometers (t t' Q 12. 12, 5 130.0 i3- 5 14. o 14. 5 15. o i5-5 i6.o 16. 5 17. o i7-5 i8.o | 40 16 23 40 40 41 ii 16 27 50 4i 42 6 13 22 42 43 2 8 15 21 -36 43 44 + I 4 9 17 24 42 44 45 4 5 II 19 27 53 45 46 7 + 3 I 6 12 18 46 47 10 6 4- 3 i 7 H 20 35 47 48 12 9 6 + 2 - 2 - 8 16 23 40 48 49 14 ii 9 5 + i 3 10 18 25 -46 49 50 17 14 ii 8 5 o 5 ii 20 28 -58 50 19 16 14 ii 8+4 6 12 18 52 21 18 16 13 ii j 7 4- 3 i 6 13 19 34 52 53 23 20. 18 16 13 10 7 + 2 2 5 15 21 -38 53 54 25 23 20 18 16 13 10 6 H- 2 8 16 23 54 55 27 25 23 20 18 15 12 9 6 + 2 3 9 17 55 56 28 26 25 22 20 ' 18 15 12 9 5 + 1 4 10 56 57 3 28 26 24 22 1 20 18 15 12 9 5 o 4 57 58 3i 3 28 26 24 22 20 18 15 12 9 + 4 58 59 33 32 30 28 26 24 22 20 18 15 12 8 -f 4 59 60 35 33 32 3 28 26 24 22 20 18 15 12 8 60 61 36 35 33 32 30 28 26 2 4 22 20 18 15 12 61 62 38 35 34 32 30 28 26 24 22 20 18 15 62 63 39 38 37 35 34 32 30 28 26 24 22 20 18 63 64 39 38 37 35 34 32 30 28 27 24 22 20 64 65 42 41 40 38 37 35 34 32 3 28 27 25 23 65 66 44 43 41 40 38 37 35 34 32 30 2 9 27 25 66 67 45 44 43 41 40 39 37 36 34 32 31 29 27 67 68 46 45 44 43 42 40 39 38 36 34 33 31 29 68 69 48 47 46 45 43 . 42 40 39 38 36 34 33 31 69 70 49 48 49 47 48 46 47 $ 43 42 43 42 39 38 39 36 38 g 33 35 70 72 52 51 50 49 47 46- 45 44 43 40 38 37 72 73 53 52 5 49 48 46 45 44 43 41 40 38 73 74 54 53 52 50 49 48 47 45 44 43 41 40 74 75 56 55 54 53 52 50 49 48 47 45 44 43 42 75 76 I 56 57 55 56 54 53 54 52 53 50 52 49 48 50 47 49 46 48 J3 43 45 77 79 i? 60 57 59 58 55 57 53 55 52 54 53 5 52 49 48 49 9 78 79 80 62 61 60 59 58 57 56 55 54 53 52 51 50 80 t 12. 12. 5 130.0 13 * 5 14. o i4-5 15. o I5 .5 i6.o i6.5 17. o I7- 5 i8.o t Temperature of the dew point, in degrees Fahrenheit. OJ 5 si "*"* Difference between the dry and wet thermometers (t <'). A Q i8.o 19. o 20. 2I.0 22. 23. o 24. o 25. o 26. o 270.0 28. o 29. o 30. o | 55 -17 47 55 56 10 27 1 56 57 4 16 57 58 o 9 30 58 59 4-4 3 -18 59 60 8 o 13 34 60 61 12 + 4 - 6 20 61 62 15 8 II 39 62 63 18 12 4-4 6 21 63 64 20 15 8 o 12 --44 64 65 23 18 12 4-4 5 23 65 66 25 20 15 8 12 -49 66 67 27 23 18 12 4-4 6 24 67 68 2 9 25 20 15 8 i 13 -52 68 69 31 27 23 18 12 4-4 5 24 69 70 33 29 25 21 15 9 13 55 70 72 73 35 i 33 35 28 3 32 2 28 18 21 24 12 16 19 4-5 9 13 5 o 4-5 24 12 4 55 24 72 73 74 40 37 34 30 26 22 16 9 12 53 74 75 42 39 36 32 29 24 19 13 4-5 4 23 75 76 43 38 34 31 27 22 17 10 i ii 49 76 77 45 42 40 % 33 29 25 20 14 4-6 5 22 77 78 47 44 41 38 35 31 28 23 17 ii 4* 2 IO 44 78 79 48 46 43 40 37 34 30 26 21 15 7 - 4 20 79 80 50 47 45 42 39 36 32 28 24 18 12 4-3 8 80 t i8.o 19. o 20. 21. 22. 23. o 24. o 25. o 26. 27. o 28. 29. o 30. o t Temperature of the dew point, in degrees Fahrenheit. 1 Difference between the dry and wet thermometers ( t t' ). 1 a 10.0 2.0 3-o 4.o 50.0 6. o 7.o 8.o 9.o 10. II.0 12. O | So 79 77 76 74 73 72 70 68 67 65 63 62 80 Si 80 78 77 75 74 73 7i 70 68 66 65 63 81 82 Si 79 78 77 75 74 72 69 68 66 6 4 82 83 82 So 79 78 76 75 73 72 70 69 67 65 83 84 83 Si So 79 77 76 74 73 70 68 6 7 84 85 84 82 81 80 78 77 75 74 72 7i 69 68 85 86 85 83 82 81 79 78 i 76 75 73 72 71 69 86 87 86 84 83 82 So 79 ! 78 76 74 73 72 70 87 88 87 85 84 83 81 So 79 77 75 74 73 88 89 88 86 85 84 82 81 So 78 76 76 74 72 89 90 89 87 86 85 84 82 81 79 78 77 75 74 90 92 90 88 89 87 88 86 87 85 86 8 82 83 80 82 g 78 79 76 77 75 76 92 93 92 9 1 89 88 87 85 84 83 81 So 78 77 93 94 93 92 90 89 88 86 85 84 82 81 80 78 94 95 94 93 9i 90 89 87 86 85 83 82 81 79 95 96 94 92 90 88 87 86 84 83 82 80 96 96 95 93 92 90 88 87 86 84 83 81 97 98 97 96 94 93 92 89 88 87 85 84 83 98 99 98 97 95 94 93 92 90 89 88 86 85 84 99 IOO 99 98 96 95 94 93 91 90 89 87 86 85 IOO IOI IOO 99 97 96 95 94 92 90 88 87 86 IOI 102 IOI IOO 98 97 96 95 93 92 90 88 87 102 103 102 IOI 99 98 97 96 94 93 92 89 88 103 104 103 102 IOO 99 98 97 96 94 93 92 90 89 104 105 104 I0 3 IOI IOO 99 98 97 95 94 93 9i 90 105 1 06 105 104 1 02 IOI IOO 99 98 96 95 94 93 106 107 106 105 103 102 IOI IOO 99 97 96 95 94 92 107 108 107 1 06 104 I0 3 102 IOI IOO 98 96 93 108 109 1 08 107 105 104 103 102 IOI 99 98 97 96 94 109 IIO 109 108 107 105 104 103 102 IOI 99 98 97 96 IIO in IIO 109 108 106 105 104 103 102 IOO 99 98 97 III 112 in IIO 109 107 106 105 104 103 IOI IOO 99 98 112 "3 112 III no 108 107 106 105 104 102 ioi IOO 99 "3 114 "3 112 in 109 108 107 106 105 103 IO2 IOI IOO 114 115 114 "3 112 IIO 109 108 107 106 I5 103 102 IOI 115 116 "5 114 "3 III IIO 109 108 107 106 104 103 102 116 117 116 "5 114 112 in IIO 109 108 107 105 104 103 117 118 117 116 "5 "3 112 III no 109 1 08 106 105 104 118 119 118 117 116 114 "3 112 in no 109 107 106 105 119 120 119 118 117 "5 114 "3 112 in IIO 108 107 106 120 121 120 119 118 117 "5 114 "3 112 til IIO 108 107 121 122 121 120 119 118 116 115 114 "3 112 in 109 108 122 123 122 121 120 119 117 116 lie 114 "3 112 IIO 109 123 124 123 122 121 120 118 117 116 114 "3 III IIO 124 125 124 I2 3 122 121 119 118 117 116 "5 114 112 III 125 126 125 124 I2 3 122 1 20 119 118 117 1x6 "5 114 112 126 127 126 125 124 I2 3 121 120 119 1.8 117 116 "5 "3 127 128 127 126 "5 124 122 121 120 119 118 117 116 114 128 I2 9 128 127 126 125 123 122 121 1 20 119 118 117 115 I2 9 130 I2 9 128 127 126 124 123 122 121 120 119 118 117 130 I 3 I2 9 128 127 125 124 I2 3 122 121 120 119 118 132 130 I2 9 T28 126 125 124 123 122 121 120 119 I 3 2 133 I 3 2 130 129 128 126 "5 124 123 122 121 120 133 134 133 I 3 2 130 I2 9 127 126 125 124 123 122 121 134 135 134 133 132 I3I 130 128 127 126 125 124 123 122 135 136 135 134 133 132 I2 9 128 127 126 125 124 123 136 137 136 135 134 133 132 130 129 128 '27 126 125 124 ^37 138 137 136 135 134 133 130 129 128 127 126 "5 138 139 138 137 I 3 6 135 134 132 130 129 128 127 126 139 140 139 138 137 I 3 6 135 133 132 131 130 I2 9 128 127 140 t ,0.0 2-0 3-o 4-o 5 0. 6.o 7.o 8.o 9.o 10. ,,0.0 12. ; 10 Temperature of the dew point, in degrees Fahrenheit. 5 7 Difference between the dry and wet thermometers ( t f ). xj "" >, 1 | "" >, p 12. O I 3 0.o 14. o I5<>.0 i6.o 17. o i8.o 19. O 20. 2I.0 22. O 23. o 240.0 5 80 62 60 58 56 54 52 50 47 45 42 39 36 32 so 81 63 61 59 57 55 53 51 49 47 44 41 38 35 81 82 64 62 61 59 57 53 50 48 45 43 40 37 82 83 65 64 62 60 58 56 54 52 50 47 44 42 39 83 84 67 65 63 61 59 57 55 53 49 46 43 84 85 68 66 64 62 61 59 57 55 53 50 48 45 42 85 86 69 67 66 64 62 60 58 56 54 52 49 47 44 86 87 70 68 67 65 63 61 59 57 55 53 48 46 87 88 7 68 66 64 63 6r 59 53 50 48 88 89 72 69 67 66 64 62 60 58 56 54 52 ' 49 89 90 74 72 70 69 67 65 63 62 60 58 56 53 51 90 92 75 76 73 74 72 73 70 69 67 68 65 66 63 64 61 62 59 60 ii 53 54 92 93 77 75 74 72 69 67 66 64 62 60 58 56 93 94 78 77 75 73 72 70 69 67 65 63 61 59 57 94 95 79 78 76 ' 75 73 7i 70 68 66 64 63 61 59 95 96 80 79 77 76 74 73 69 68 66 64 62 60 96 97 81 80 78 77 75 74 72 69 67 65 63 61 97 98 99 8 3 84 81 82 80 81 78 79 3 \l 73 75 72 73 70 68 70 67 68 65 66 63 64 98 99 IOO 85 83 82 80 79 77 76 74 73 71 69 67 66 IOO IOI 86 84 83 82 80 79 77 75 74 72 69 67 IOI 102 87 85 84 83 81 80 78 77 75 73 72 70 68 102 103 104 88 89 85 82 83 81 82 79 81 78 79 . 76 78 11 73 74 71 73 70 103 104 105 90 89 87 86 85 83 82 80 79 77 76 74 72 105 106 90 89 87 86 84 83 81 80 74 106 107 108 92 93 92 90 89 87 88 85 84 85 83 84 81 82 8? 78 9 107 108 109 94 93 92 90 89 88 86 85 83 82 80 79 77 109 IIO 96 94 93 92 90 89 87 86 85 83 82 80 79 no III 97 94 93 90 89 87 86 84 83 81 80 in 112 98 96 94 92 90 88 87 85 83 81 112 "3 99 97 96 95 93 92 91 89 88 87 85 84 82 "3 114 IOO 99 97 96 95 93 92 89 88 86 85 83 114 115 IOI IOO 98 97 96 94 93 92 90 89 88 86 85 "5 116 102 IOI 99 98 97 95 94 93 91 90 89 87 86 116 117 103 102 IOO 99 98 96 94 93 91 90 88 87 117 118 104 103 IOI IOO 99 97 96 95 94 92 90 88 118 119 105 104 103 IOI IOO 99 97 96 95 93 92 91 89 119 120 106 105 104 1 02 IOI IOO 99 97 96 95 93 92 90 120 121 107 106 105 103 102 IOI IOO 98 97 96 94 93 92 121 122 108 107 106 105 103 102 IOI 99 98 97 96 94 93 122 123 109 108 107 106 104 103 102 IOI 99 98 95 I 94 123 124 IIO 109 108 107 105 104 103 1 02 IOO 99 98 96 95 124 "5 III IIO 109 1 08 106 105 104 103 IOI IOO 99 98 96 "5 126 112 III IIO 109 108 106 105 104 103 IOI IOO 99 97 126 127 113 112 in no 109 107 106 105 104 102 IOI IOO 98 127 128 114 "3 112 in IIO 108 107 106 105 103 IO2 IOI IOO 128 129 114 "3 112 III IIO 108 107 106 105 103 1 02 IOI I2 9 130 117 1I5 114 "3 112 in 109 108 107 106 104 103 1 02 130 118 116 115 114 "3 112 IIO 109 108 107 106 104 103 132 133 119 1 20 117 118 116 117 IS 114 H5 "3 114 112 "3 IIO in 109 IIO 108 109 107 108 105 106 104 105 132 133 134 121 120 1 18 117 116 115 114 112 III IIO 109 108 106 134 135 122 121 119 118 117 116 "5 "3 112 in IIO 109 107 135 I 3 6 I2 3 122 1 20 119 118 117 116 "5 "3 112 III IIO 108 136 137 124 123 121 1 20 119 118 117 116 114 "3 112 in no 137 138 125 124 122 121 120 119 118 117 "5 114 "3 112 in 138 139 126 125 124 122 121 1 20 119 118 117 "5 114 "3 112 139 I4O 127 126 "5 123 122 121 120 119 118 116 115 114 113 140 t 12. 13. o 14. o 15. o i6.o 17. o i8.o 19. o 20. 21. O 22. 230.0 240.0 t 11 Temperature of the dew point, in degrees Fahrenheit. fi CO w "** Difference between the dry and wet thermometers ( I f ). ~~ 1 24. o 25. o 26. o 270.0 28.0 29. o 30. o 31. o 32. o 33-o 340.0 35-o 36. o Q 80 3 2 28 24 18 12 3 II 40 80 81 35 31 26 22 16 8 2 18 1 81 82 37 33 29 25 19 13 + 4 7 35 82 83 39 35 27 22 i? 9 i 15 83 84 37 34 30 25 20 14 + 5 5 30 84 85 42 39 36 32 28 23 18 ii + i 13 85 86 44 38 35 30 26 21 15 7 - 5 25 86 87 46 43 40 37 33 29 24 19 12 + 3 ii 87 88 48 45 42 39 31 27 22 16 8 2 21 88 89 49 47 44 38 34 30 25 20 13 + 4 IO 44 89 90 5i 48 46 43 40 36 32 28 23 18 10 I 20 90 53 50 47 45 42 38 35 31 26 21 15 + 6 7 91 92 54 52 49 46 44 37 34 29 25 19 12 + I 92 93 56 53 51 48 46 43 39 36 32 28 23 16 8 93 94 57 55 53 50 47 45 42 38 35 31 26 20 13 94 95 59 56 54 52 49 46 44 40 37 33 29 24 18 95 96 60 58 56 53 51 48 46 43 39 36 32 27 22 96 97 61 59 57 55 53 50 47 45 41 38 34 30 25 97 98 63 61 59 57 52 49 47 44 40 37 33 28 98 99 64 62 60 58 56 54 48 46 43 39 35 31 99 IOO 66 64 62 60 57 55 53 50 48 45 4i 38 34 IOO 101 67 65 63 61 59 57 54 52 49 47 44 40 37 IOI 102 68 66 63 61 58 56 54 49 46 43 39 102 103 70 68 66 64 62 60 58 55 53 50 48 45 I0 3 104 71 69 67 65 63 61 59 57 55 52 5 47 44 104 105 72 70 69 67 65 63 61 59 56 54 52 49 46 105 106 74 7 2 70 68 66 64 62 60 56 53 51 48 106 107 75 73 71 70 68 66 64 62 60 57 55 52 50 107 106 76 74 73 71 69 67 65 63 61 59 57 54 52 108 109 77 76 74 72 69 67 65 63 61 58 56 54 109 IIO 79 77 75 74 72 70 68 66 64 62 60 58 55 no III 80 78 77 73 70 68 66 64 62 59 57 in 112 81 79 78 76 74 73 69 67 65 63 61 59 112 "3 82 81 79 77 76 74 72 69 67 65 63 60 "3 114 83 82 80 79 77 75 74 72 70 68 66 64 62 114 115 116 117 85 86 87 U 85 82 80 81 82 78 80 81 77 78 79 78 73 11 72 73 74 70 72 68 69 66 4 64 "5 116 117 118 88 87 85 84 82 81 79 77 76 74 72 70 68 118 119 89 88 86 85 83 82 80 79 77 75 74 72 70 119 120 90 89 88 86 85 83 82 80 78 77 75 73 7 1 120 121 92 90 89 87 86 84 83 81 80 78 76 74 73 121 122 93 91 90 89 87 86 84 83 81 79 78 76 74 122 J23 94 93 90 88 87 85 84 82 81 79 77 '75 I2 3 124 95 94 92 89 88 87 85 83 82 80 79 77 124 "5 96 95 93 92 9i 89 88 86 85 83 82 80 78 125 126 96 93 92 90 89 87 86 84 83 81 80 126 I2V 98 97 96 94 93 92 90 89 87 86 84 83 81 127 128 IOO 98 97 96 94 93 90 88 87 85 84 82 128 129 IOI 99 98 97 95 94 93 90 88 87 85 84 I2 9 I 3 1 02 IOI 99 98 97 95 94 92 91 89 88 86 85 130 103 102 IOO 99 98 96 95 94 92 89 88 86 131 I 3 2 104 I0 3 IOI IOO 99 97 96 95 93 92 90 89 87 I 3 2 133 105 104 103 IOI IOO 99 97 96 94 93 92 90 89 133 134 106 105 104 102 IOI IOO 98 97 96 94 93 9i 90 134 135 107 106 105 104 102 IOI IOO 98 97 95 94 93 9i 135 136 108 107 106 105 103 102 IOI 99 98 97 95 94 92 136 IIO 108 107 106 104 103 IO2 IOI 99 98 96 95 94 137 138 III 109 108 107 106 104 I0 3 IO2 IOO 99 98 96 95 138 139 112 IIO 109 108 107 105 104 103 IOI IOO 99 97 96 139 140 H3 112 IIO 109 108 107 105 104 103 IOI IOO 99 97 140 t 24.0 25. o 260.0 270.0 28.0 29. o 30. o 31. o 32. o 33-o 34 o.o 35. o [360.0 t 1 12 Temperature of the dew point, in degrees Fahrenheit. t-l o> 1 Difference between the dry and wet thermometers ( t t' ). O Q 36^.0 370.0 38. o 390.0 40. o 41. o 42. o 43 o.o 440.0 45-o 46. o 470.0 48. o c Q 89 44 89 90 17 90 91 7 33 91 92 + i -13 92 93 8 4 26 93 94 13 + 4 IO 94 95 18 10 I 20 95 96 22 15 4- 6 6 40 96 97 25 19 12 4- i 15 97 98 28 23 17 8 4 -29 98 99 31 27 21 14 4-4 II 99 IOO 34 30 25 19 II o 21 IOO 101 37 32 28 23 16 4-7 6 42 101 102 39 35 31 26 20 13 + 3 -14 1 02 103 41 38 34 29 24 18 10 2 28 103 104 44 40 37 32 28 22 15 4-6 9 104 105 46 43 39 35 31 26 20 12 + i 19 105 106 48 45 42 38 34 29 24 17 9 4 -38 106 107 50 47 44 40 37 32 28 22 15 4-4 12 107 108 52 49 46 43 39 31 26 19 ii 24 108 109 54 48 45 42 38 34 30 24 17 + 8 6 -56 109 no 55 53 50 47 44 41 37 33 28 21 H + 4 15 no in 57 54 52 49 46 43 39 31 25 19 ii i in 112 59 56 48 45 42 38 34 29 24 16 + 7 112 "3 60 58 56 53 50 47 44 41 37 32 28 21 14 1*3 114 62 60 58 55 52 50 47 43 40 35 3i 26 19 114 115 116 117 118 64 65 67 68 62 63 11 6 5 ? 63 64 57 8 62 1 52 57 49 51 53 55 46 48 50 52 42 45 47 49 38 8 34 37 40 43 30 33 36 39 24 28 34 "5 116 117 118 119 70 68 66 64 61 59 57 54 48 45 42 37 119 120 71 69 67 65 63 61 59 56 53 50 47 44 40 1 20 121 73 71 69 67 63 60 58 55 52 50 47 43 121 122 74 72 70 68 66 64 62 60 57 54 ' 52 49 46 122 123 124 75 77 74 75 72 73 70 71 68 69 66 67 64 65 61 63 i? 1 3 51 53 48 50 123 124 "5 78 76 75 73 7i 69 67 65 63 60 58 55 52 I25 126 80 78 76 74 73 69 6 4 62 60 57 54 126 127 128 81 82 I? 78 79 76 77 74 75 72 74 70 72 70 66 68 64 65 62 63 59 61 1 128 129 84 82 80 79 77 75 73 69 67 65 63 60 I2 9 130 85 83 82 80 78 76 75 73 7i 69 67 64 62 I 3 86 85 83 81 80 78 76 74 72 70 68 66 64 131 132 133 I 7 89 86 83 84 81 82 I? 78 79 76 77 74 75 72 73 70 68 69 67 132 133 134 90 88 87 85 84 82 80 79 77 75 73 69 134 135 91 90 88 87 85 83 82 80 78 76 75 73 7i 135 136 92 89 88 86 85 83 81 80 78 76 74 72 136 137 94 92 89 88 86 84 83 81 79 78 76 74 137 138 95 93 92 90 89 87 86 84 82 81 79 77 75 138 139 96 95 93 92 90 89 87 85 84 82 80 79 77 139 140 97 96 94 93 9i 90 88 87 85 83 82 80 78 140 t 36. o 37- o 38. o 39-o 40. o 41. o 42. o 430.0 44. o 45-o 460.0 47. o 48. o t 13 Relative humidity, per cent. J Difference between the dry and wet thermometers (t t'}. A 1 0.2 o. 4 ' o.6 o.8 i.o *., i.4 ,0.6 ,=.8 2.0 2. 2 2-4 2. 6 Q 40 58 0> 40 39 61 g (t-f) 39 -38 62 *" ^ -38 37 65 3 1 5 O. I 6. 2 37 -36 66 35 36 -35 69 38 50 62 35 34 71 43 A.Q 64 34 33 73 45 -48 67 33 32 74 48 22 ^f- *f 47 f' 69 32 3 1 75 51 2O 46 71 3i 30 "f 76 78 79 80 81 82 S 8 63 30 33 37 40 43 if. 17 21 25 28 45 44 43 42 41 72 74 76 78 79 45 49 52 55 57 30 29 28 27 -26 25 24 83 66 40 49 32 15 24 23 84 67 35 19 23 22 84 68 53 39 23 22 21 85 70 56 42 27 21 20 86 71 58 44 30 2O 19 86 73 59 47 34 20 I 9 18 87 74 61 49 36 23 18 17 88 75 63 52 39 27 16 17 16 88 77 65 54 42 31 20 16 15 89 78 66 56 45 34 23 12 15 14 89 79 68 48 37 27 16 14 13 90 80 69 60 5 40 3 20 13 12 90 80 62 S 2 43 24 14 12 II 91 81 72 64 54 45 36 27 18 II IO 9i 82 73 64 55 47 39 30 21 13 IO Q 83 74 65 57 49 42 25 17 9 8 92 84 75 59 51 43 36 28 2O 12 8 7 92 84 76 68 61 53 45 37 31 23 16 - 7 6 93 85 77 7 63 55 48 40 34 27 20 12 6 4 93 93 86 86 78 79 72 64 65 57 59 50 52 42 45 1 3 32 11 16 19 9 13 5 4 2 93 87 80 73 67 60 54 47 34 29 23 16 3 2 94 87 81 74 68 62 56 49 43 37 32 26 20 2 I 94 88 82 75 69 63 57 45 39 33 29 23 I 94 88 82 76 7i 65 59 53 47 42 36 3 24 O I 94 89 83 77 72 66 6! 56 49 44 38 33 28 I 2 95 89 84 78 73 68 62 57 46 36 31 2 3 95 90 84 79 74 69 64 59 53 48 43 38 33 3 4 95 90 85 80 75 70 65 60 55 50 45 40 35 4 5 95 90 86 81 76 71 66 62 57 52 47 43 38 5 6 95 91 86 81 77 72 68 63 59 54 49 45 6 7 95 91 86 82 78 73 69 64 60 56 47 43 7 8 96 92 87 83 79 74 70 66 61 57 53 49 45 8 9 96 92 87 83 79 75 67 63 59 55 47 9 10 96 92 88 4 80 76 72 68 64 60 56 52 48 10 ii 96 . 92 88 85 81 77 73 69 65 62 58 54 50 ii 12 96 93 89 85 81 78 74 70 66 63 59 56 52 12 I 3 96 93 89 86 82 78 75 68 64 61 57 53 13 14 96 93 90 86 83 79 76 72 69 65 62 59 55 14 15 97 93 90 87 83 80 77 73 70 67 63 60 57 15 16 97 94 90 87 84 81 77 74 - 68 61 58 16 17 97 94 87 84 81 78 75 72 69 66 63 60 17 18 97 94 91 88 85 82 79 76 73 70 67 64 61 18 19 97 94 9i 88 85 82 79 76 74 68 65 62 19 20 97 94 9i 89 86 83 80 77 74 ' 72 69 66 63 20 t 0.2 o. 4 o.6 o.8 ,=.0 I 2 -.4 ,.6 ,'.8 2.0 2. 2 2. 4 2. 6 t 14 Relative humidity, per cent. J Difference between the dry and wet thermometers (t f ). 1 Q 20.6 20.8 3 o. 3. 2 3- 4 3. 6 3-8 40.0 4 .2 40.4 I 2 20 14 7 2 I 23 17 ii I O 26 20 15 9 I 2 J5 2 18 21 Ii 7 ii 4 I 2 3 33 28 24 19 14 9 4 3 4 35 3i 26 22 18 13 8 4 5 6 7 38 43 33 Ii 28 31 23 a 21 23 24 16 19 22 ii 15 18 7 10 14 6 9 5 1 7 8 45 4i 36 31 27 24 21 17 12 9 8 9 47 43 38 33 30 26 24 20 16 12 9 10 48 45 41 35 32 29 26 23 19 15 10 ii 50 46 43 38 34 31 28 24 22 18 ii 12 13 52 53 48 50 JS 43 37 39 30 32 26 29 24 25 21 22 12 13 H 55 5i 48 44 38 34 28 24 14 15 57 53 50 46 43 40 36 34 30 27 15 16 58 54 5 2 49 45 42 38 36 33 30 16 17 60 56 53 51 47 44 40 38 35 32 17 18 61 57 55 52 49 46 42 40 37 34 18 19 62 59 56 54 48 45 42 39 36 19 20 63 60 58 55 53 50 47 44 4i 38 20 < 2 o.6 2. 8 3-o 3-2 3- 4 30.6 3. 8 4.o 4. 2 40.4 t t 4. 6 4. 8 50.0 5-2 5- 4 5. 6 50.8 6.o 6. 2 60.4 t 8 4 8 9 8 4 9 10 ii 7 4 10 u M 10 7 3 ii 12 17 14 10 7 3 12 13 20 17 13 10 7 3 13 14 23 19 16 13 10 6 3 g 25 27 22 25 19 21 16 19 II 9 13 6 10 3 6 3 15 16 Js 2 9 31 3 24 27 21 24 22 15 18 13 15 10 13 7 10 4 7 17 18 19 34 31 28 26 24 21 18 16 13 10 19 20 36 33 31 27 26 23 22 18 15 13 20 t 40.6 4. 8 5-o 5-2 5-4 5-6 5. 8 60.0 6. 2 6. 4 t 15 Relative humidity, per cent. to "*"* Difference between the dry and wet thermometers (t t'). to "*"* 1 o. 5 10.0 i.5 20.0 2 o. 5 3.o 3-5 4.o 4- 5 50.0 5- 5 6.o 1 20 93 86 79 72 65 58 5I 44 37 30 23 18 20 21 93 86 79 73 66 59 52 45 39 32 25 19 21 22 93 86 80 73 67 60 54 47 34 28 21 22 23 24 93 94 87 87 80 81 74 75 68 69 61 62 49 50 43 44 1 30 32 2 23 24 25 94 88 82 76 70 63 57 52 46 40 34 28 25 26 94 88 82 76 71 65 59 53 47 42 36 3 26 27 94 89 83 72 66 60 54 49 43 38 3 2 27 28 95 8 9 83 72 67 61 56 50 45 39 34 28 29 95 89 84 78 73 67 62 57 52 47 36 29 30 95 90 84 79 73 68 63 58 53 48 43 38 30 31 32 95 95 90 90 85 79 80 74 75 69 70 64 65 59 61 3 49 51 9 40 31 32 33 95 90 85 80 76 66 62 57 52 47 43 33 34 95 90 85 81 76 72 67 63 58 53 49 44 34 35 95 9i 86 81 77 72 68 64 59 54 50 45 35 37 96 96 9i 86 87 82 82 77 78 73 74 69 69 64 60 61 52 9 36 37 38 96 92 87 83 79 75 70 66 62 57 53 50 38 39 96 92 88 83 79 75 7i 67 63 58 54 51 39 40 96 92 88 84 80 76 72 68 63 59 55 52 40 4 1 96 92 88 84 80 76 72 68 64 60 57 53 4 1 42 96 92 88 84 81 77 73 69 61 58 54 42 43 96 92 88 85 81 77 74 70 66 62 58 55 43 44 96 92 88 85 8r 78 74 70 67 63 59 56 44 9 9 96 96 92 93 93 93 89 89 89 89 85 86 82 82 83 83 78 79 79 79 75 1 72 72 73 67 68 69 69 64 66 60 61 62 63 I i 49 97 93 90 86 83 80 76 73 70 67 63 60 49 50 97 93 90 87 83 80 77 74 70 67 64 61 50 97 93 9 84 81 74 68 62 52 97 94 90 87 84 81 78 75 72 69 66 63 52 53 54 97 97 94 94 87 88 84 85 81 82 78 79 9 72 73 69 70 66 67 63 64 53 54 55 56 97 97 94 94 91 91 88 88 |5 82 82 79 80 76 77 73 74 70 68 68 65 65 11 57 97 94 9 1 88 86 83 80 77 74 7 1 69 66 57 58 97 94 89 86 83 80 78 75 72 69 67 58 59 97 94 92 89 86 83 81 78 75 72 70 67 59 - 60 61 97 97 94 94 92 92 89 89 86 87 8$ 81 81 78 78 9 73 73 70 68 68 60 61 ~ 62 97 95 92 89 87 84 81 79 76 74 7 l 69 62 63 97 95 92 89 87 84 82 79 77 74 72 6 9 63 64 97 95 92 90 87 85 82 79 77 74 72 70 64 65 97 95 92 90 87 85 82 80 77 75 72 70 65 66 97 95 9 2 90 87 85 82 80 78 75 73 66 6 7 98 95 93 90 88 85 83 80 78 76 73 71 67 68 98 95 93 90 88 85 83 Si 78 76 74 7 1 68 69 98 95 93 90 88 86 83 81 78 76 74 72 69 70 98 95 93 90 88 86 83 81 79 77 74 72 70 7 1 98 95 93 88 86 84 81 79 77 75 72 71 72 98 95 93 9 1 88 86 84 82 79 77 75 73 72 73 98 95 93 91 88 86 84 82 80 78 75 73 73 74 98 95 93 91 88 86 84 82 80 78 76 74 74 75 98 95 93 91 89 87 84 82 80 78 76 74 75 76 98 95 93 91 89 87 85 82 80 78 76 74 76 77 98 95 93 89 87 85 83 80 78 76 74 77 78 98 96 93 g\ 89 87 85 83 81 79 77 75 78 79 98 96 94 91 89 87 85 83 81 79 77 75 79 80 98 96 94 9 2 89 87 85 83 3 1 79 77 - 75 80 < 00.5 ,0.0 ,.5 2.0 2. 5 3'o 3- 5 4 .o 4. 5 5-o 5-5 6.o t 16 Relative humidity, per cent. N Jq Difference between the dry and wet thermometers (t t' . ~! t*> >> ;-, p 6.o 60. 5 7 .o 7-5 8.o 8. 5 9 .o 9-5 10. 10. 5 no.o i..5 12. | 19 16 8 2 19 20 18 ii 5 20 21 19 14 8 21 22 21 15 ii 4 22 23 24 17 13 7 I 23 24 26 20 16 10 4 24 25 28 22 17 12 7 2 25 26 30 24 19 14 10 4 26 2 7 32 27 22 16 12 7 2 27 28 34 29 24 19 14 10 5 28 29 36 31 26 21 16 ii 7 3 29 30 38 33 28 23 18 13 10 5 30 40 35 30 25 21 16 ii 8 3 31 32 37 32 28 23 18 14 10 6 I 32 33 43 38 34 29 25 20 16 12 8 4 33 34 44 40 35 31 27 22 18 14 10 7 3 34 1 45 47 48 50 43 3 37 38 40 42 33 | 38 29 30 32 34 24 26 28 3 20 22 24 26 16 18 20 22 12 14 16 18 8 10 12 15 5 7 9 ii I 4 6 8 2 5 11 II 39 5 1 47 43 39 35 32 28 24 20 17 13 9 7 39 40 52 48 44 41 37 33 30 26 22 19 15 ii 8 40 41 53 49 46 42 38 35 31 28 24 21 17 13 10 41 42 54 50 47 43 40 36 33 29 26 22 19 15 12 42 43 55 51 48 45 38 34 31 28 2 4 21 17 14 43 44 56 52 49 46 43 39 36 32 29 26 23 19 16 44 45 57 53 50 47 44 40 34 31 28 24 21 18 45 46 58 54 51 48 45 42 35 32 2 9 26 23 20 46 47 48 59 60 P 52 53 49 50 46 47 43 44 40 37 38 34 31 32 28 29 5 22 2 3 JS 49 60 57 54 48 45 42 39 36 33 30 28 25 49 50 61 58 55 52 49 46 43 40 37 35 32 29 26 50 52 62 59 60 57 53 54 50 51 48 8 42 43 39 40 37 33 30 32 28 29 51 52 53 63 61 58 55 52 49 47 44 41 38 36 33 31 53 54 64 61 59 56 53 50 48 45 42 39 37 34 32 54 55 65 62 59 57 54 5I 49 46 43 40 38 36 33 55 56 65 63 60 57 55 52 50 47 44 42 39 37 56 57 58 67 64 64 61 61 59 55 56 53 53 50 51 48 49 8 43 44 40 42 38 39 37 59 67 65 62 60 57 54 52 49 47 45 43 40 38 59 60 68 65 63 60 58 55 53 50 48 46 44 4i 39 60 61 68 66 63 61 58 56 54 51 49 47 44 42 40 61 62 63 69 69 66 67 64 64 61 62 59 60 57 57 54 55 52 53 50 5i 47 48 35 46 43 44 41 42 62 63 64 70 67 65 62 60 58 56 53 49 47 45 43 64 65 70 68 65 63 61 59 56 54 52 50 48 46 44 65 66 71 68 66 63 61 59 57 55 53 49 47 45 66 68 7i 69 66 67 64 65 62 63 60 60 58 58 53 54 52 49 50 9 8 68 69 72 70 67 65 63 61 59 57 55 53 49 47 69 70 72 70 68 66 64 62 60 57 55 53 52 5 48 70 71 72 70 68 66 64 62 60 58 56 54 52 50 48 7* 72 73 71 69 67 6S 63 61 59 57 55 53 49 72 73 73 71 69 65 63 61 59 57 55 53 52 50 73 74 74 72 70 68 66 64 62 60 58 56 54 52 50 74 75 74 72 70 68 66 64 62 60 58 56 55 53 51 75 76 74 72 70 68 66 64 63 61 59 57 53 52 76 77 74 73 71 69 67 65 63 61 59 57 56 54 52 77 78 75 73 71 69 67 65 63 62 60 58 56 54 53 78 79 75 73 7i 70 68 66 64 62 60 58 57 55 53 79 80 75 73 72 70 68 66 64 63 61 59 57 55 54 80 | 6.o 6- 5 7.o 7- 5 S.o 8. 5 9.o 9- 5 10. 10. 5 ,,0.0 n-5 12. t 17 Relative humidity, per cent. J Difference between the dry and wet thermometers (t t' ). A Q 12. 12. 5 13. o 13 5 14. o i4- 5 15. o i5- 5 i6.o 160-5 170.0 i7-5 i8.o Q 40 8 6 2 40 41 10 8 4 i 41 42 12 9 6 3 42 43 14 ii 8 6 2 43 44 16 13 10 7 5 2 44 45 18 15 12 9 6 4 i 45 46 20 17 14 ii 8 6 3 46 47 22 19 16 13 10 7 2 47 48 23 20 18 15 12 9 6 4 2 48 49 25 22 19 17 14 ii 8 5 4 i 49 50 26 23 21 18 16 13 10 7 5 3 i 50 51 28 25 22 20 17 15 12 9 7 5 3 52 2 9 26 24 21 19 16 13 ii 9 6 4 2 52 53 31 28 25 23 20 18 15 13 10 8 5 4 2 53 54 32 29 27 24 22 19 17 14 12 10 7 5 3 54 1 33 34 31 32 28 30 26 27 23 2 5 21 22 18 20 16 17 14 15 ii 13 9 ii 7 8 4 6 56 36 33 31 28 26 24 21 19 17 12 10 8 57 58 37 34 32 2 9 27 25 23 20 18 16 14 12 10 58 59 38 36 33 31 29 26 24 22 20 17 15 13 ii 59 60 61 39 40 i 34 35 32 33 30 31 28 29 25 27 23 24 21 22 19 20 17 18 3 13 14 60 61 62 39 37 34 32 30 28 26 24 22 20 18 16 62 63 42 40 38 33 31 29 27 25 23 21 I 9 17 63 64 43 38 36 34 32 3 28 26 2 4 22 20 18 64 65 44 42 39 37 35 33 31 29 27 25 24 22 20 65 66 45 42 40 38 36 34 32 30 29 25 23 21 66 67 45 43 39 37 33 32 30 28 26 24 22 67 68 46 44 42 40 38 36 34 33 31 29 27 25 23 68 69 47 45 43 39 37 35 33 32 30 28 26 24 69 70 48 46 44 42 40 38 36 34 33 31 29 27 26 70 71 48 46 45 43 41 39 37 34 32 30 28 27 71 72 49 47 45 43 42 40 38 36 35 33 31 30 28 72 73 5 48 46 44 4 2 41 39 37 34 32 30 29 73 74 50 48 47 45 43 4i 40 38 36 35 33 31 30 74 75 76 52 49 50 g 46 46 44 45 42 43 40 39 39 1 35 34 35 32 33 31 31 M 77 52 50 49 47 45 44 42 40 39 37 34 32 77 78 53 51 49 48 46 44 43 41 39 38 36 35 33 78 79 53 52 50 48 47 45 43 42 40 39 37 36 34 79 80 54 52 51 49 47 45 44 42 41 39 38 36 35 80 t 12. 12. 5 13. o i3-5 14. o *4-5 ,5'.. I5- 5 160.0 i6. 5 170.0 i7-5 i8.o t 18 Relative humidity, per cent. o Q) ,g Difference between the dry and wet thermometers (t t"). 72 "" >, 1 "" >, Q i8.o 19. o 20. 21. 22. 23. o 24. o 25. o 26.0 27. o 28. o 29. o 30. o Q 55 4 i 55 56 6 3 S^ 57 8 57 58 10 6 2 58 59 ii 8 4 59 60 13 9 , I 60 61 62 \i 10 12 8 3 5 I 61 62 63 17 13 9 6 3 63 64 18 15 ii 7 4 I 64 65 20 16 12 9 6 2 65 66 21 17 H 10 7 4 I 66 67 22 19 12 g 5 2 67 68 23 20 16 13 10 6 4 o 68 69 24 21 18 ii 8 5 2 69 70 26 22 19 16 12 9 6 3 o 70 71 27 23 20 17 H 10 7 5 2 72 28 24 21 18 15 12 9 6 3 72 73 2 9 25 22 19 16 13 10 7 4 2 73 74 30 26 23 20 17 H ii 8 6 3 o 74 75 31 27 24 21 18 15 12 9 7 4 2 75 76 31 28 2 5 22 19 16 14 ii 8 5 3 o 76 77 32 29 26 23 20 17 12 9 6 4 2 77 78 33 30 27 24 21 18 16 13 10 8 5 3 o 78 79 34 31 28 25 22 19 17 H ii 9 6 4 2 79 80 35 32 29 26 23 20 18 15 13 10 7 5 3 80 < i8.o 19. o 20. 21. 22. '23. o 24. o 25. o 26. o 27. o 28. o 29. o 30. o t 19 Relative humidity, per cent. e Difference between the dry and wet thermometers ( t V ). a, II. 4 Is 0, i i- a. I o a, >, " O PH h &, L - I > a, j O PL. | cS Oj H -, K 05 * cj cC a ^ Q > Z > M -! "* M ^j 30 .0097 045 30 .166 60 517 90 408 1 20 3- 425 29 .OIO I .047 31 173 61 536 91 453 121 3-522 -58 .0018 28 .Oil 2 .049 32 .180 62 555 92 499 122 3.621 57 .0019 27 .Oil 3 .052 33 .187 63 93 546 123 3-723 -56 .O020 26 .012 4 054 34 64 ^5. 94 595 124 3-827 55 54 .0021 OO22 -25 24 013 .013 1 057 059 $ .203 .211 65 66 .616 .638 95 96 645 .696 "5 126 3- 933 4.042 53 .0024 23 .014 7 .062 37 .219 67 .661 97 749 127 4-154 52 .O026 22 .015 8 -065 38 .228 68 .684 98 .803 128 4.268 .O027 21 .016 9 .068 39 237 69 .707 99 859 129 4-385 50 .0029 2O .017 10 .071 40 .2 4 6 70 732 100 .916 130 4-504 49 0031 19 .018 n .074 .256 71 757 IOI 975 4.627 48 0033 18 .018 12 078 42 .266 72 783 1 02 035 132 4-752 47 0035 -17 .019 13 .081 43 277 73 .810 103 .097 133 4.880 -46 .0038 16 .020 14 -085 44 .288 74 -838 104 .100 134 5.011 45 .0040 15 .022 15 .088 45 .298 75 .866 105 -225 135 5-145 44 .0043 14 -023 16 .092 46 .310 76 : 8 ^ 106 .292 136 5.282 43 .0046 13 .024 17 .096 47 -322 77 107 -360 137 5.422 42 .0048 12 .025 18 . IOI 48 334 78 957 108 431 138 5. 565 41 .0051 II .026 19 .105 49 347 79 989 109 -502 139 5-712 40 0054 IO .028 20 . no 50 360 80 .022 no 2.576 140 5.862 39 .0058 9 .029 21 .114 51 373 81 .056 III 2.652 -38 .OO6l 8 031 22 .119 52 387 82 .091 112 2.730 37 .0065 7 032 23 .124 53 .402 83 .127 113 2.810 -36 .0069 - 6 034 24 .130 54 .417 84 163 114 2.891 35 .0073 5 035 25 135 55 432 85 .202 "5 2-975 34 0078 4 037 26 .141 56 -448 86 .241 116 3.061 33 .0082 3 039 27 .147 57 465 87 .281 117 3- H9 32 .0087 2 .041 28 153 58 -481 88 322 118 3-239 -3i 0092 I 043 29 159 59 499 89 364 119 3-331 Vapor Pressure 24 Correction of dew point for pressure. i 30"- 29". 28". 27"' 26". as". 24". 23"- 22' ' . 2l". 20". I 9 ". 18". 5 i .000 .000 + 001 + .001 + .001 +.002 +.002 +.003 4-003 +.003 '+.004 +.004 +.004 i 2 .000 .000 .001 .002 .002 .003 , .004 005 .006 .007 .007 .OO8 .009 2 3 .001 .000 .001 .002 .003 .004 .006 .007 .008 .009 .010 I -on .012 3 I .001 .000 .002 .003 .005 .006 .008 .009 Oil .012 .014 .015 .017 4 5 001 -J-. 001 .002 .004 .006 .008 | .010 .012 .014 015 .017 .Oig .021 5 6 .001 .001 .003 .005 .008 .010 ; .012 I .014 .016 .019 021 .023 .025 6 7 001 .001 .003 .006 .009 .012 i -014 ! .017 .019 .022 .024 .027 .030 7 S 001 .001 .004 .007 .010 .013 \ .016 .Oig .022 .025 .028 .031 034 S 9 .001 .002 .005 .008 .012 015 ' .Ol8 .022 .025 .028 .032 035 038 9 10 002 . 002 .005 .009 .013 .017 ! .020 .024 .027 .031 035 039 043 10 1 1 .002 .002 .006 010 .014 .018 .022 .026 .031 035 039 043 .047 ii ta .003 OO2 .006 OIO .015 Oig ' -024 .028 .032 037 .041 .046 .050 12 '3 .003 .002 .006 on .016 .021 .026 .030 .040 045 050 055 13 1 4 004 .002 .007 012 .017 . 022 . 028 033 .038 043 .048 54 059 14 C5 -.004 .002 .007 .013 .019 .024 : .030 035 .041 .046 .052 058 -06 3 15 1 6 -.004 OO2 .008 .OI4 .020 .026 i .032 038 .044 .049 055 .061 j .067 16 i? -.004 .002 .008 .015 .021 .027 ! .034 .O4O .046 053 059 . .065 j .072 1 7 18 .004 .002 .009 016 .022 .029 .036 .042 .049 .056 .062 .069 .076 18 19 005 OO2 .009 .017 .024 .031 .038 045 .052 059 .066 . 073 . 080 19 20 005 .003 .010 .018 .026 .033 1 .041 .048 055 .063 070 .078 .085 20 21 -.005 .003 on 019 .027 .034 .042 .050 057 .066 073 .081 .089 21 22 -.005 .003 .Oil .020 .028 .036 i .044 .052 .061 .069 .077 .085 .093 22 23 .005 .003 .012 .021 .029 .038 .046 55 .063 .072 08l .089 .098 23 24 -.005 .004 .013 .021 .030 039 .048 057 .066 075 .084 093 .102 24 25 -.006 .004 .013 O22 .032 .041 . 050 060 .069 .078 .088 .097 .106 25 26 .006 .004 .013 .023 033 . 043 . 052 .062 .072 .081 .091 IOI .III 26 27 .006 .004 .014 .024 034 .044 .054 .065 075 .085 095 .105 "5 27 28 -.006 .004 .015 .025 .036 i .046 056 .067 .077 .088 .098 .109 .119 28 29 .007 .004 .015 .026 037 -048 .059 i .069 .080 .091 . 102 "3 .124 29 30 -.007 .004 016 .027 038 ' .049 .061 .072 .083 .094 .105 .117 .128 30 31 -.007 .005 .016 028 039 051 .063 .074 .086 .097 .109 . 121 .132 31 32 .007 .005 .017 .029 .041 053 .065 .077 .089 . IOI 113 125 137 32 33 .007 .005 .017 .030 .042 ! -054 .067 .079 .092 .104 .Il6 .129 .141 33 34 -.008 .005 .018 .031 043 ; -056 .069 .082 .094 .107 . I2O 133 145 34 35 .008 .005 018 .032 045 i .058 .071 .084 .097 . no .123 137 -150 35 |6 .008 .005 .019 .032 046 i -059 073 .086 . too .114 .127 .141 154 36 .008 .006 .019 033 .047 .061 075 .089 .103 .117 131 145 158 37 38 .009 .006 .020 034 .049 063 .077 .091 .106 . 120 134 .149 .163 38 39 40 .009 -.009 .006 .006 .021 .021 035 036 .050 .051 .065 .066 .079 .081 .094 .096 .109 . Ill .123 .126 138 .142 153 157 .167 .172 39 40 Dew point Pressure Correction. D TO .- SEP MAR 21 JUtt 251 JON 9 1960 S RECTO UJ MAY