425. Covenant construed by reference to circumstances.

'Impositions', and other similar words which may be used in a covenant by the tenant to pay rates and taxes1, will not be construed so widely as to include obligations which cannot reasonably be supposed to have been within the contemplation of the parties when they entered into the lease2; and their effect may be restricted by other provisions of the lease which specifically impose upon the landlord expenses which they would otherwise include. Thus, an agreement by the landlord to do outside repairs may relieve a tenant who has agreed to pay 'impositions' from liability for the expenses