Mariner's compass, the invention of, A. Humboldt, xl, 242.
Marl, apparatus for analyzing, W. B. Rogers, xxvii, 299.f
— from Farmington, Ct., analysis of, E. Hitchcock, xxxvi, 176.
— in New York, iii, 237.
— for manure, from near the Chesapeake Bay, xx, 411.
— of New Jersey, identical with the chalk of England, S. G. Morton, xxii, 90.
— — —, analysis of, xvii, 277.
— — —, on the application of, to agriculture, J. Pierce, vi, 237.
—, shell, in Maryland, xxvii, 3.
— beds of Virginia, xi, 54.