Note 15 — Chapter IV · CONJECTURES IN REGARD TO METEORIC EPOCHS.

"This is a remarkable example of a stone arriving on the earth with a temperature approaching that of the interplanetary spaces. Aerolites containing much iron, a substance which conducts heat well, get thoroughly heated by their passage through the atmosphere. But the stony aerolites, containing less iron, conducting heat badly, preserve in their interior the temperature of the locality from which they fall; their surface only is heated, and generally fused. When the stones are large, the excessive cold of their interior portion, which must be nearly that of interplanetary space, is remarked; but when small, they remain hot for some time."—Dr. Phipson.