Meteorological Journal, Kept by the Assistant Secretary, at the Apartments of the Royal Society, by Order of the President and Council

METEOROLOGICAL JOURNAL, KEPT BY THE ASSISTANT SECRETARY, AT THE APARTMENTS OF THE ROYAL SOCIETY, BY ORDER OF THE PRESIDENT AND COUNCIL. OBSERVANDA. Height of the Cistern of the Barometer above the plinth at Waterloo Bridge...83 feet 2 inches. above the mean level of the sea .........................97 feet. Height of the receiver of the Rain Gauge above the court of Somerset House ..79 feet. The External Thermometer is 2 feet higher than the Barometer Cistern. The Thermometers are graduated to Fahrenheit's scale. The Barometer is divided into inches and tenths. The Hours of Observation are of Mean Time, the day beginning at Midnight. The daily observations of the Barometer are not corrected. The monthly means are corrected for capillarity and temperature by the Table contained in Mr. Baily's paper in Phil. Trans. for 1837. ## Meteorological Journal for January and February, 1840 ### Observations | Date | Time | Barometer (inches) | Temperature (°F) | Wind Direction | |------|------|-------------------|-----------------|---------------| | | | | | | ### Remarks - **A.M.:** Overcast—light rain and wind. P.M.: Fine—light clouds. - **Evening:** Fine and starlight. ### Mean Barometer Corrected - **9 A.M.:** 29.577 - **3 P.M.:** 29.660 - **9 A.M.:** 29.879 - **3 P.M.:** 29.861 ## Meteorological Journal for March and April, 1840 ### March | Time | Barometer (corrected) | Att. Ther. | Barometer (incorrected) | Att. Ther. | External Thermometers | REMARKS | |------------|-----------------------|------------|-------------------------|------------|----------------------|---------| | 9 o'clock A.M. | 30.374 | 36.2 | 30.332 | 37.0 | 32.7 | ENE | | | 30.430 | 38.0 | 30.366 | 37.2 | 36.0 | NE | | | 30.430 | 38.0 | 30.360 | 37.2 | 37.4 | NE | | | 30.408 | 36.9 | 30.348 | 38.9 | 35.4 | NE | | | 30.446 | 38.3 | 30.442 | 40.4 | 36.7 | NE | | | 30.564 | 38.6 | 30.544 | 40.6 | 37.2 | NE | | | 30.650 | 38.9 | 30.604 | 41.0 | 37.0 | NE | | | 30.640 | 38.8 | 30.570 | 41.4 | 37.7 | NE | | | 30.392 | 41.7 | 30.304 | 43.7 | 35.3 | NE | | | 30.276 | 45.2 | 30.298 | 45.8 | 42.5 | NE | | | 30.276 | 44.4 | 30.218 | 46.4 | 40.8 | NE | | | 30.098 | 45.3 | 30.014 | 47.9 | 45.0 | NE | | | 30.044 | 46.0 | 30.036 | 48.7 | 45.8 | NE | | | 29.974 | 45.7 | 29.840 | 47.0 | 42.4 | NE | | | 30.042 | 45.8 | 30.118 | 46.6 | 43.0 | NE | | | 30.282 | 44.8 | 30.244 | 45.2 | 40.4 | NE | | | 30.166 | 43.9 | 30.124 | 45.4 | 41.7 | NE | | | 30.190 | 44.6 | 30.230 | 46.2 | 40.0 | NE | | | 30.312 | 43.7 | 30.268 | 45.8 | 41.3 | NE | | | 30.404 | 45.8 | 30.410 | 44.4 | 37.1 | NE | | | 30.302 | 42.9 | 30.214 | 44.0 | 39.3 | NE | | | 29.992 | 43.8 | 30.030 | 43.8 | 38.0 | NE | | | 30.144 | 43.5 | 30.138 | 41.8 | 36.7 | NE | | | 30.292 | 40.5 | 30.286 | 40.0 | 37.4 | NE | | | 30.316 | 38.5 | 30.246 | 40.6 | 35.3 | NE | | | 30.116 | 39.7 | 30.028 | 40.8 | 38.7 | NE | | | 29.782 | 40.7 | 29.746 | 42.0 | 39.5 | NE | | | 29.886 | 45.3 | 29.900 | 45.2 | 46.7 | NE | | | 29.840 | 46.0 | 29.818 | 46.8 | 46.8 | NE | | MEAN | 30.245 | 41.8 | 30.214 | 43.1 | 35.3 | NE | ### April | Time | Barometer (corrected) | Att. Ther. | Barometer (incorrected) | Att. Ther. | External Thermometers | REMARKS | |------------|-----------------------|------------|-------------------------|------------|----------------------|---------| | 9 o'clock A.M. | 29.664 | 46.2 | 29.606 | 47.9 | 44.4 | S | | | 29.720 | 45.8 | 29.754 | 49.0 | 43.6 | S | | | 30.024 | 46.8 | 29.996 | 49.9 | 42.3 | S | | | 29.960 | 45.8 | 29.924 | 46.0 | 39.8 | S | | | 30.044 | 45.8 | 30.004 | 48.0 | 45.2 | S | | | 29.798 | 51.9 | 29.634 | 50.2 | 49.3 | S | | | 29.552 | 50.7 | 29.628 | 49.7 | 43.4 | S | | | 29.995 | 47.5 | 30.028 | 46.3 | 41.0 | S | | | 30.256 | 45.0 | 30.202 | 46.9 | 42.3 | S | | | 30.400 | 48.2 | 30.344 | 48.0 | 45.4 | S | | | 30.250 | 50.0 | 30.134 | 48.8 | 46.7 | S | | | 30.050 | 48.0 | 30.004 | 49.8 | 47.4 | S | | | 29.912 | 49.2 | 29.836 | 52.0 | 50.8 | S | | | 29.808 | 52.3 | 29.780 | 52.3 | 46.9 | S | | | 29.936 | 54.4 | 29.928 | 54.6 | 59.2 | S | | | 30.108 | 60.2 | 30.086 | 56.3 | 55.7 | S | | | 30.188 | 57.8 | 30.116 | 54.4 | 50.5 | S | | | 30.040 | 60.8 | 29.955 | 53.3 | 47.0 | S | | | 29.922 | 49.5 | 29.846 | 52.3 | 42.8 | S | | | 29.892 | 56.3 | 29.850 | 54.8 | 51.2 | S | | | 30.074 | 56.0 | 30.076 | 56.4 | 60.7 | S | | | 30.224 | 55.8 | 30.266 | 57.9 | 55.5 | S | | | 30.348 | 59.2 | 30.304 | 59.8 | 65.2 | S | | | 30.290 | 67.0 | 30.212 | 61.5 | 58.8 | S | | | 30.174 | 66.7 | 30.120 | 62.0 | 61.8 | S | | | 30.312 | 67.8 | 30.284 | 63.4 | 59.5 | S | | | 30.356 | 63.0 | 30.300 | 64.2 | 62.5 | S | | | 30.300 | 68.8 | 30.240 | 63.5 | 57.5 | S | | | 29.298 | 67.0 | 30.260 | 64.6 | 67.0 | S | | | 30.324 | 65.2 | 30.272 | 64.0 | 69.2 | S | | MEAN | 30.077 | 55.2 | 30.037 | 54.3 | 59.5 | S | ### Mean Barometer Corrected - **9 A.M.:** 30.216 - **3 P.M.:** 30.171 --- **Note:** The table provides detailed meteorological data for March and April 1840, including barometric pressure, external thermometers, and remarks about weather conditions. | Date | Time | Barometer (A.M.) | Barometer (P.M.) | Temperature (°F) | Temperature (°C) | Remarks | |------|------|-----------------|-----------------|-----------------|-----------------|---------| | May 1 | 9 A.M. | 30.212 | 30.266 | 74.7 | 23.7 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 1 | 3 P.M. | 29.866 | 29.866 | 65.9 | 18.8 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 3 | 9 A.M. | 30.106 | 30.100 | 73.7 | 23.2 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 3 | 3 P.M. | 29.978 | 29.978 | 69.0 | 20.6 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 5 | 9 A.M. | 30.040 | 30.034 | 60.3 | 15.6 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 5 | 3 P.M. | 29.970 | 29.970 | 64.3 | 17.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 7 | 9 A.M. | 29.932 | 29.932 | 62.8 | 16.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 7 | 3 P.M. | 29.932 | 29.932 | 62.8 | 16.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 9 | 9 A.M. | 30.018 | 30.012 | 64.0 | 17.8 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 9 | 3 P.M. | 29.970 | 29.970 | 64.3 | 17.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 11 | 9 A.M. | 30.054 | 30.050 | 62.7 | 16.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 11 | 3 P.M. | 29.970 | 29.970 | 64.3 | 17.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 13 | 9 A.M. | 29.992 | 29.992 | 66.8 | 19.4 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 13 | 3 P.M. | 29.992 | 29.992 | 66.8 | 19.4 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 15 | 9 A.M. | 30.054 | 30.050 | 62.7 | 16.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 15 | 3 P.M. | 29.970 | 29.970 | 64.3 | 17.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 17 | 9 A.M. | 29.836 | 29.832 | 76.8 | 24.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 17 | 3 P.M. | 29.836 | 29.832 | 76.8 | 24.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 19 | 9 A.M. | 29.870 | 29.866 | 75.2 | 24.1 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 19 | 3 P.M. | 29.870 | 29.866 | 75.2 | 24.1 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 21 | 9 A.M. | 30.018 | 30.014 | 63.2 | 17.3 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 21 | 3 P.M. | 29.990 | 29.990 | 64.4 | 17.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 23 | 9 A.M. | 30.054 | 30.050 | 62.7 | 16.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 23 | 3 P.M. | 29.970 | 29.970 | 64.3 | 17.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 25 | 9 A.M. | 29.870 | 29.866 | 75.2 | 24.1 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 25 | 3 P.M. | 29.870 | 29.866 | 75.2 | 24.1 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 27 | 9 A.M. | 30.018 | 30.014 | 63.2 | 17.3 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 27 | 3 P.M. | 29.990 | 29.990 | 64.4 | 17.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 29 | 9 A.M. | 30.054 | 30.050 | 62.7 | 16.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 29 | 3 P.M. | 29.970 | 29.970 | 64.3 | 17.9 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 31 | 9 A.M. | 29.870 | 29.866 | 75.2 | 24.1 | Fine and cloudless throughout the day. Evening, Fine & starlight. | | May 31 | 3 P.M. | 29.870 | 29.866 | 75.2 | 24.1 | Fine and cloudless throughout the day. Evening, Fine & starlight. | --- **Mean Barometer corrected:** 29.903 **Sum:** 2,329