336 PROFESSOR FORBES ON THE CLIMATE OF EDINBURGH. 
35. With a view to trace more intelligibly the specific characters of the dif- 
ferent seasons, and in the hope of perhaps distinguishing in them something of 
a periodic or recurring character, I had the whole of these monthly temperatures 
projected in the form of fifty-six annual curves of temperature. The result, 
however, does not seem at present to warrant the labour and expense of reducing 
and engraving them. Looking, however, in a general way at these curves, or at 
the numbers in the preceding table, we note three leading characteristics of any 
year. J. The mean temperature of the year, or the position of the line of abscissze 
of the curve for that year. II. The annual range due to season. III. The earli- 
ness or lateness of the season, or the period of culmination of the curve for the 
year.* We shall consider these elements of climate more particularly. 
36. I. Mean Temperature of the Year.—The mean of the whole period, 
deduced from nearly 35,000 observations, is 46°°75, or if we exclude the Dun- 
fermline observations, 46°°88.+ 

The highest annual mean was that of 1846, amounting to, . 5 : 49°60 
The lowest was that of 1799, ‘ ; F : A ; ‘ ‘ 44:44 
The range, 5°16 
The higher limit was nearly touched in 1826 and 1834; the lower limit in 1816 
and 1838.t The following table contains the order of the years, taken with 
respect to mean temperature, beginning with the highest :— 
TABLE II.—TuHE SEASONS ARRANGED ACCORDING TO THE MEAN TEMPERATURE, 
BEGINNING WITH THE HIGHEST. 
1846 8.| 1822 || 15.| 1805 || 22. {1811 || 29.) 1840 || 36.| 1815 || 43.} 1830 || 50. | 1812 
1854 9.| 1832 || 16.) 1847 || 23. ee 30.| 1801 || 37.| 1839 || 44.) 1807 || 51.| 1823 
1826 || 10.| 1843 || 17.| 1804 || 24.| 1808 || 31.|f1803 || 38.| 1797 || 45.| 1836 || 52.| 1829 
1828 || 11.| 1798 || 18.) 1824 |) 25.) 1802 || 32. ed 39. |{1819 || 46.) 1837 || 53.| 1814 
1806 |} 12.| 1831 |} 19.) 1833 || 26. |f{1809 || 33.) 1849 || 40. ere 47.| 1800 || 54.| 1838 
1825 || 13.| 1821 || 20.| 1827 || 27. oe 34.) 1813 || 41.} 1810 || 48.| 1817 || 55.) 1816 
1842 || 14.) 1818 |} 21.| 1850 |} 28.| 1844 |) 35.) 1796 || 42.| 1820 || 49.| 1795 || 56.) 1799 

SANGO eed 
















* In the usual approximate expression for the annual curve of temperature represented by the 
curve of sines, where ¢ is the temperature of any day of the year, « the time reckoned from the 
commencement of the year, then, ¢=A+B sin (x+u,). The three constants, A, B, and u,, refer to 
the three particulars specified in the text. The equation to the annual curve will be more fully 
considered farther on (in § 6). 
+ It will be seen how nearly this coincides with Mr Jarpine’s deductions from the temperature 
of springs, viz., 47°08. (Art. 15, note). 
{ The mean temperature of Greenwich for seventy-nine years (1771-1849) is estimated by Mr 
GLAIsHER at 48°:29, or only 1°54 above that of Edinburgh. The fluctuation of the mean annual 
temperature at Greenwich was 6°:2, or within the period of the Edinburgh observations (1795-1850) 
5°6. (Phil. Trans., 1850.) 
