Bridges;

Making any additions to or alterations in buildings reasonably necessary or proper to enable the same to be let;

Erection of buildings in substitution for buildings within an urban sanitary district taken by a local or other public authority, or for buildings taken under compulsory powers, but so that no more money be expended than the amount received for the building taken and the site thereof;

The rebuilding of the principal mansion house on the settled land: Provided that the sum to be applied under this sub-section shall not exceed one-half of the annual rental of the settled land.