Differential calculus, on the first principles of, T. Strong, xlv, 269.
—, equations of the second order, integration of, xlii, 273.
[Dikes,] observed to have a crescent shape in Connecticut, J. G. Percival, xlvi, 205.
— of trap, cause of crescent form, H. D. Rogers, xlv, 334.
— —, in the Connecticut valley, vi, 47, 56.f
— —, of Maine, of four different ages, C. T. Jackson, xxxvi, 145.
— —, in Massachusetts, near Lowell, and at Nahant, &c., xxvii, 342.
— —, in Michigan, D. Houghton, xli, 184.
— —, in granite, New Hampshire, numerous, O. P. Hubbard, xxxiv, 105.f