[237], l. 3 from bottom, for “representing,” read “separating.”

[241], l. 2, for “localities,” read “locality.”

[242], l. 7, omit “and c e, the parapets.”

[243], l. 9, for “embankment,” read “abutment.”

[244], l. 9, for “is thus,” read “is found thus.”

[245], l. 17, for “latter,” read “batter.”

[249], l. 23, for “common hydraulic,” read “common mortar, hydraulic.”

[249], l. 27, for “argyle magnesia,” read “argil, magnesia.”

[251], l. 16, for “7½ to 2,” read “1½ to 2.”

[254], last l., for “corners,” read “courses.”