—, artificial, produced by mixed metals, xiii, 171.
—, —, a freezing mixture for, xii, 195.
—, extraordinary seasons of, N. Webster, xxviii, 183.
— at New Haven in 1766, 1767, xxviii, 183.
— at Hartford in 1780, xxviii, 186.
—, extreme, at Plattsburgh, N. Y., iii, 366; xi, 195.
— in Maine, 1817, mercury frozen by, xxxi, 161.
— on Lake Superior, ix, 395.
— of the winter of 1825-6, x, 399.
— of January, 1835, xxviii, 177.