THE ROYAL SOCIETY, AND AT THE ROYAL OBSERVATORY, GREENWICH. 595 
1812, 1814, 1816, 1837, 1839 and 1845, and the mean of their temperatures was 
43°-l. 
The coldest spring-, during the whole period, was in the year 1837, and its mean 
temperature was 40°' 9. 
The years distinguished by hot springs were 1779, 1780, 1811, 1822, 1830, 1841 
and 1848, and the mean of their temperatures was 50°'0. 
The hottest spring, during the whole period, was 1779, and its mean temperature 
was 50°' 8. 
The mean temperature of summer, from all the observations, is 60°'0. The years 
distinguished by cold summers were 1771, 1784, 1799, 1812, 1813, 1814, 1816, 1817, 
and the mean of their temperatures was 56°'9. 
The years distinguished by hot summers were 1778, 1779, 1780, 1781, 1818, 1826, 
1831, 1834, 1835, 1842 and 1846, and the mean of their temperatures was 63°'2. The 
coldest summer wuthin the period was that in the year 1816, and its mean tempera- 
ture was 55°'2. The hottest summer within the period was that in the year 1846, and 
its mean temperature was 64°'3. 
The mean temperature of autumn, from all the observations, is 49°'3. The years 
distinguished by cold autumns were 1771, 1782, 1786, 1789 and 1829, and the mean 
of their temperatures was 45°'9. 
The years distinguished by hot autumns were 1779, 1795, 1804, 1806, 1811, 1818, 
1821, 1822, 1831 and 1846, and the mean of their temperatures was 52°'3. The coldest 
autumn within the period was that in the year 1786, and its mean temperature was 
44°'2. The hottest autumn within the period was that in the year 1718, and its mean 
temperature was 54°'5. 
The mean temperature of winter, from all the observations, was 37°'6. The years 
distinguished by cold winters were 1783, 1784, 1794, 1796, 1813 and 1829; the 
mean of their temperatures was 32°'6. 
The years distinguished by warm winters were 1778, 1755, 1803, 1806, 1821, 1827, 
1833, 1845 and 1848, and the mean of their temperatures was 42°* 1. 
The coldest winter within the period was that in the year 1794, and its mean tem- 
perature was 31°'6. 
The warmest winter wdthin the period was that in the year 1795, and its mean value 
was 43°'2. The winters of the years 1833 and 1845 were remarkably warm, being 
both of the value of 43°* 1. 
By taking the difference between the mean temperature of each period from all the 
observations, and the mean temperature for the same period, in every year, the next 
Table is formed. 
4 G 2 
