Stone, to weather well, should be laid with its bedding (lamination) horizontal, as it was first laid down by nature in the quarry. The stone, moreover, will offer greater resistance to pressure if laid in this manner, and, it is said, will stand a greater amount of heat without disintegrating. This is important in cities where any building is liable to have its walls highly heated by neighboring burning structures.

Some stones that are liable to be destroyed by the effects of frost on first being taken from the quarries, are no longer so after being exposed for some time to the air, having lost their quarry water through evaporation. This difference is very manifest between stones quarried in summer and those quarried in winter. It has frequently happened that stones of good quality have been entirely ruined by hard freezing immediately after being taken from the quarry; while, if they are quarried during the warm season of the year and have an opportunity to lose their quarry water by evaporation prior to cold weather, they withstand freezing very well. This particularly applies to some marbles and limestones. This change is accounted for by the claim put forward, that the quarry water of the stones carries in solution carbonate of lime and silica, which is deposited in the cavities of the rock as evaporation proceeds. Thus additional cementing material is added, rendering the rock more compact. This also will account for the hardening of some stones after being quarried a short time. When first quarried they are soft, easily sawed and worked into any desirable shape; but after the evaporation of their quarry water, they become hard and very durable.

Table I gives the physical properties of many of the most im--portant varieties and grades of building stone found in the United States.