Opinion by

It is not seriously contended that any error was committed in the construction of the lease as it is written, or in the application to the forfeiture clause of the principle settled in Wills v. The Manufacturer’s Natural Gas Co., 130 Pa. 222; nor can it be successfully maintained that the mere assignment of such lease by the appellant to the Ten Mile Oil & Gas Company discharged him from liability on his covenants therein: Frank *568v. Maguire, 42 Pa. 82; Washington Natural Gas Co. v. Johnson, 123 Pa. 576. But it is claimed that certain matters are stated in the affidavit of defence which show the written lease ought to be reformed so as to admit of a construction which will release him. By the construction contended for, and based on the proposed modification of the lease, the only duty of the appellant thereunder was to transfer it to an oil and gas company, to be organized for the purpose of testing the adjacent territory, and his assignee acquired an option, for which it gave nothing, and incurred no liability to the lessor. It is very evident that a reformation which will accomplish such results, and practically destroy the written and sealed agreement of the parties, must have something more substantial to support it than inferences founded on equivocal averments. When a party to an action, in order to prevent judgment against him for the claim, is required to file his sworn answer to it, he is expected to state clearly and distinctly the facts which constitute his defence; and when the nature and character of the defence are such that the law exacts “clear, precise, and indubitable evidence ” to sustain it, the importance of a plain and concise statement of it becomes obvious. Injustice is not likely to result from the exaction of such a statement of the defence, especially where it is apparent, as in this case, that it was prepared by competent counsel, who knew what was required, and presumably presented it in as favorable light for their client as his recollection and conscience warranted. Certainly a party who seeks to set aside his written obligation on the ground that he entered into it on the faith of a contemporaneous parol agreement cannot justly complain if he is required to state such agreement with clearness and precision.

The affidavit of defence in this case does not sustain the claims that are made upon it, or authorize any material modification of the lease. It does not allege that the execution of the lease was induced by any fraud or misrepresentation of the lessor, or contain any distinct averment of an agreement by which the lessee was to be released from the liability imposed by its written terms. The lessor’s knowledge of his lessee’s intentions respecting the development of the property and the transfer of the lease does not destroy the latter’s express covenant to commence operations on the demised premises within *569one year, or thereafter to pay, while in default, the sum of $400 per annum to his lessor. It is not stated in the affidavit of defence that the lessor at any time declared the lease forfeited for noncompliance with its terms, but it does appear therein that the appellant’s assignee, by its sale and transfer of the lease to Brown, recognized it as in full force. It is true that the appellant in his affidavit says that his lessor encouraged Brown and his associates to make a further test of the territory for the production of oil and gas, and that he “ waived to them the forfeiture of the said leasehold, and accepted from them the sum of four hundred dollars, and thereby gave to them the privilege of holding his land for another year.” This averment is, however, entirely consistent with the view that the lessor was so desirous of having the work done for which he contracted that he refrained from exercising his right to declare the lease forfeited for delay in the performance of its covenants. It will not be seriously affirmed, we think, that, by the lessor’s failure to forfeit the lease for the default of his lessee, he lost his right to enforce it.

We might specify other defects and omissions in the affidavit which make it unsatisfactory, and clearly insufficient to justify the proposed modification of the written lease, but, as the whole subject is so intelligently presented and considered in the able and exhaustive opinion of the learned judge of the court below, we regard further specification of them as unnecessary. The affidavit appears to have been drawn with a view to create the impression that the execution of the lease was induced by certain agreements between the parties, which render its enforcement, according to its terms, unjust and oppressive, and that it has been forfeited by the conduct of the lessor. But a careful examination of the affidavit fails to disclose any specific averment of such agreement, or of any word or act of the lessor indicative of a purpose on his part to annul the lease. It is an ingenious and misleading affidavit, but it is clearly insufficient to prevent judgment for the claim founded on a breach of the appellant’s distinct covenant to commence operations on the demised premises within one year, or thereafter to pay the sum named therein as compensation for his default.

The specifications of error are overruled.

Judgment affirmed.