+---------------------------------------------------------------+ | Cold Period. | Warm Period. | Cold Period. | Warm Period. | |---------------|---------------|---------------|---------------| |1786 48 deg..53 |1791 48 deg..963|1796 48 deg..678|1801 50 deg..432| |1787 47 deg..88 |1792 48 deg..44 |1797 48 deg..135|1802 50 deg..794| |1788 47 deg..676|1793 50 deg..96 |1798 49 deg..471|1803 50 deg..24 | |1789 47 deg..68 |1794 50 deg..768|1799 48 deg..291|1804 48 deg..328| |1790 46 deg..53 |1795 50 deg..173|1800 49 deg..989|1805 50 deg..792| |---------------|---------------|---------------|---------------| |Mean of | | | | |period 47 deg..659|Mean 49 deg..901|Mean 48 deg..910|Mean 50 deg..117| |---------------|---------------|---------------|---------------| |---------------|---------------|---------------|---------------| |1806 47 deg..982|1811 50 deg..76 |1816 47 deg..113|1821 48 deg..15 | |1807 48 deg..132|1812 45 deg..28 |1817 46 deg..277|1822 49 deg..81 | |1808 49 deg..485|1813 47 deg..702|1818 48 deg..009|1823 47 deg..58 | |1809 47 deg..92 |1814 48 deg..279|1819 50 deg..75 |1824 49 deg..25 | |1810 49 deg..001|1815 47 deg..607|1820 48 deg..70 |1825 50 deg..99 | |---------------|---------------|---------------|---------------| |Mean 48 deg..505|Mean 47 deg..925|Mean 48 deg..169|Mean 49 deg..15 | +---------------------------------------------------------------+ The tables of Dr. Hildreth, from 1826 to 1854, inclusive, furnish, generally, evidence of a like character. There are, however, an anomaly or two which will be observed. From 1826 to 1830, the mean is high during the period when spots were at a maximum. But that maximum embraced a much less number of spots than the two succeeding ones. A contrast appears in the tables of Dr. Hildreth, during the early period, for Dr. Holyoke's register, for 1827, puts it _below the mean_, but Dr. Hildreth's one of the _highest of the half century_. In 1835 commenced a period when the spots were much more numerous, and from 1835 to 1838, inclusive, the seasons were correspondingly below the mean. From that period to 1844 a gradual and slightly irregular rise took place, excepting the year 1843, when another cold year intervened. The table of earthquakes, published by the British Association, closes with 1842, and I have not access to any others. The occurrence of such cold years, in the warm period, at intervals during the two centuries previous, and in 1812, and onward, and evidently owing to increased volcanic action beneath the western portion of the northern hemisphere, justifies the belief that the low temperature of 1843 was owing to the same cause. The following are the means from the tables of Dr. Hildreth: