Turning to the second table, compiled for the most part from brickmakers’ circulars, and from the original results obtained for the late Building Exhibition, at the Agricultural Hall, all the experiments, we believe, having been carried out by Mr. David Kirkaldy, it will be noted that great variation in strength is apparent, following the different kinds of bricks. The highest result, 1064.2 tons per square foot, was obtained on a blue Staffordshire brick, though that is very closely run by bricks made from slate débris (1056.2 tons) from South Wales. The lowest result, 139.5 tons per square foot, was from a Worcester brick. STRENGTH OF BRICKS.--II. -------------------+----------------+--------------------+------------------ | | | Mean stress of | | Dimensions, | six samples in Locality. | Description. | Inches. |tons per square ft | | +---------+-------- | | | Cracked | Crushed -------------------+----------------+--------------------+---------+-------- West Bromwich | Blue | 2.74, 9.03 × 4.36 | 548.6 | 1064.2 | | | | „ „ | Blue (another |} 2.80, 8.75 × 4.12 | 260.7 | 651.0 | make) |} | | | | | | „ „ | White glazed, |} | | | “Terra |} | | | Metallic,” |} 3.10, 8.80 × 4.22}| 225.0 | 273.7 | recessed |} 3.16, 8.70 × 4.34}| | | both sides |} | | | | | | „ „ | Blue vitrified | 2.55, 9.03 × 4.30 | 245.1 | 654.9 | | | | {| “Pressed,” |} | | Worcester {| recessed top |} 3.20, 9.14 × 4.50 | 65.0 | 139.5 {| and bottom |} | | | | | | „ | “Builders.” |} | | | recessed top |} 3.20, 9.30 × 4.50 | 56.1 | 155.5 | and bottom |} | | | | | | Saltley, | Red, recessed |} 3.20, 8.90 × 4.35}| 138.7 | 180.5 Birmingham | one side |} 3.25, 8.95 × 4.40}| | | | | |