A Continuation of the Account of the Weather in Madeira. By Dr. Thomas Heberden. Communicated by Dr. W. Heberden, F. R. S.

LXXXI. A Continuation of the Account of the Weather in Madeira. By Dr. Thomas Heberden. Communicated by Dr. W. Heberden, F. R. S. Read May 30, 1754. Madeira, Anno 1751. | Month | Barometer | Thermometer | |-----------|-----------|-------------| | | M. H. | G. H. | L. H. | M. H. | G. H. | L. H. | | January | 29.775 | 30.1 | 29.45 | 64.354 | 69 | 62 | | February | 29.896 | 30.1 | 29.5 | 64.553 | 68 | 60 | | March | 30.002 | 30.1 | 29.7 | 64.967 | 70 | 63 | | April | 29.97 | 30.1 | 29.85 | 65.01 | 68 | 63 | | May | 29.827 | 30.05 | 29.6 | 66.822 | 70 | 63 | | June | 30 | 30.05 | 29.8 | L. W. | 70.833 | 76 | 68 | | July | 29.973 | 30.05 | 29.9 | 74.161 | 77 | 72 | | August | 29.942 | 30.05 | 29.9 | 75.709 | 78 | 72 | | September | 29.931 | 30 | 29.8 | 74.916 | 78 | 73 | | October | 29.86 | 30.05 | 29.4 | 72.774 | 76 | 68 | | November | 29.813 | 30.1 | 9.6 | 68.533 | 72 | 65 | | December | 29.807 | 30.1 | 29.3 | 63.725 | 71 | 62 | Anno 1752. | Month | Barometer | Thermometer | |-----------|-----------|-------------| | | M. H. | G. H. | L. H. | M. H. | G. H. | L. H. | | January | 29.788 | 30.1 | 29.55 | 65.254 | 68 | 62 | | February | 29.866 | 30.15 | 29.7 | 63.071 | 66 | 60 | | March | 30.026 | 30.2 | 29.75 | 66.032 | 68 | 63 | | April | 22.844 | 30.05 | 29.45 | 65.683 | 68 | 64 | | May | 29.987 | 30.15 | 29.8 | 66.37 | 69 | 64 | | June | 29.966 | 30.1 | 29.7 | 70.58 | 74 | 67 | | July | 29.999 | 30.1 | 29.9 | 72.962 | 75 | 70 | | August | 30.002 | 30.05 | 29.9 | 73.86 | 76 | 73 | | September | 30.022 | 30.1 | 29.9 | L. W. | 76.538 | 80 | 74 | | October | 29.807 | 30.1 | 29.7 | 73.08 | 78 | 69 | | November | 29.51 | 30.05 | 29.75 | L. W. | 68.3 | 73 | 64 | | December | 30.05 | 30.15 | 29.7 | 66.354 | 70 | 64 | Madeira, Madeira, Anno 1753. | Month | Barometer | Thermometer | |---------|-----------|-------------| | January | 29.904 | 63.129 | | February| 29.933 | 65.946 | | March | 29.943 | 66.967 | | April | 29.921 | 65.316 | | May | 29.896 | 66.709 | | June | 29.988 | 69.6 | Collecting the respective sums of the daily heights of the instruments throughout the year, and extracting the mean altitude, I find, The mean altitude of the barometer for each day, is 29.915 inches. Of the thermometer, 68°.918. The greatest barometrical variation, during four years and four months, has been 9 tenths of an inch, viz. from 29.3 to 30.2. For altho' in April 1751, the mercury stood at 29.1, I find, by a note in my diary, that some air having infinuated itself into the tube, I judg'd the mercury to stand 3 tenths of an inch lower than it ought. The greatest thermometrical variation, during the said time, has been 20°; viz. from 60° to 80°: But it may be observ'd, I never knew it rise so high but once; occasion'd by a very strong leste or levant wind; the extreme height, without such an accident, being never more than 78°. N. B. It may be necessary to advise, that my observations are made in the city of Funchal. The quantity of rain, which has fallen in the island of Madeira. | Anno | 1751. Inch. Dec. Pts. | 1752. Inch. Dec. Pts. | 1753. Inch. Dec. Pts. | |------|---------------------|---------------------|---------------------| | January | 5.614 | 11.452 | 5.374 | | February | .867 | 4.496 | 2.912 | | March | —— | .189 | 4.679 | | April | .011 | 2.479 | 1.604 | | May | 1.59 | .399 | .038 | | June | .022 | .860 | .284 | | July | —— | .221 | .019 | | August | —— | —— | —— | | September | 3.176 | .03 | 1.37 | | October | 1.707 | 9.897 | 2.352 | | November | 3.509 | 5.37 | 1.967 | | December | 10.483 | .308 | 2.974 | Total: 26.979 | 38.701 | 23.573 The quantity of rain, which has fallen the last seven years, from 1747. to 1753. inclusive, amounts to 214.346 inches. Therefore the mean quantity for each year is 30.62 +. The mean quantity of water for each day of the said seven years .083 +. The number of days it rain'd in the said seven years 462 The mean quantity of water for each of the days it rain'd .503 +. An account of the number of days, on which it rained, and of the greatest quantity of water, which fell in any one day of the respective month; in inches and decimal parts. | Anno | 1747 | 1748 | 1749 | 1750 | 1751 | 1752 | 1753 | |------|------|------|------|------|------|------|------| | | Days. | Quantity of water | Days. | Quantity of water | Days. | Quantity of water | Days. | Quantity of water | Days. | Quantity of water | Days. | Quantity of water | Days. | Quantity of water | | January | 17 | 5.4 | 8 | 3.055 | 6 | .586 | 15 | 1.855 | 12 | 1.553 | 14 | 2.751 | 16 | .862 | | February | 2 | .306 | 13 | 2.884 | 3 | .9 | 8 | .474 | 7 | .457 | 10 | 1.491 | 5 | 2.453 | | March | 16 | 1.384 | 8 | 2.501 | 3 | .573 | 6 | .498 | — | — | 2 | .118 | 8 | 1.342 | | April | 2 | .328 | 6 | .521 | 2 | .502 | 1 | .039 | 2 | .006 | 6 | .4 | 5 | .954 | | May | 3 | .171 | — | — | 11 | 1.018 | 5 | .618 | 5 | .432 | 2 | .385 | 1 | .038 | | June | 3 | .9 | 1 | .42 | 1 | .113 | 2 | .164 | 1 | .022 | 5 | .523 | 3 | .284 | | July | 1 | .2 | — | — | — | — | 1 | .176 | — | — | 1 | .221 | 1 | .019 | | August | 2 | .01 | 3 | 1.475 | — | — | 1 | .003 | — | — | — | — | — | — | | September | 4 | .327 | 1 | .81 | 4 | .32 | 6 | .434 | 3 | 1.5 | 1 | .03 | 8 | .742 | | October | 1 | .01 | 7 | 1.415 | 12 | .387 | 13 | .2 | 9 | .425 | 16 | 2.438 | 10 | .657 | | November | 9 | 1.151 | 4 | 1.283 | 7 | .912 | 10 | .942 | 11 | .749 | 13 | 1.031 | 4 | .959 | | December | 3 | .925 | 2 | 1.5 | 14 | 1.5 | 6 | .055 | 15 | 2.45 | 3 | .257 | 10 | .725 | Total N of days: 63 [620]