A court of equity will not refuse to enforce a contract specifically which was fair when made, by reason of the increase in value of the subject-matter ; Meehan v. Nelson, 137 Fed. 731, 70 C. C. A. 165. Where the ven dee bought property for $300, and paid one dollar down and then did nothing for nine years, and it appeared that the property had reached a value of $15,000, specific perform ance was refused; McCabe v. Matthews, 155 U. S. 550, 15 Sup. Ct. 190, 39 L. Ed. 256.
Equity will enforce a contract for the ex clusive rights under letters patent, and will enjoin the breach of a negative covenant; Hapgood v. Rosenstock, 23 Fed. 86; Adams v. Messinger, 147 Mass. 185, 17 N. E. 491, 9 Am. St. Rep. 679; Satterthwalt v. Marshall, 4 Del. Ch. 337; Corbin v. Tracy, 34 Conn. 325; including a contract to assign all future inventions relating to a certain art ; Appeal of Reese, 122 Pa. 392, 15 Atl. 807; although the agreement be oral; Searle v. Hill, 73 Ia.
367, 35 N. W. 490, 5 Am. St. Rep. 688; but not if the contract be unconscionable; Pope Mfg. Co. v. Gormully, 31 Fed. 877.
A parol agreement to assign the• right to a patent for an invention may be specifically enforced ; Pressed Steel Car Co. v. Hansan, 128 Fed: 444; and so where the inventor was an employe of the complainant, although the employment was terminable at any time by either party on notice; Mississippi Glass Co v. Franzen, 143 Fed. 501, 74 C. C. A. 135, 6 Ann. Cas. 707; but where the plaintiff has an application pending for a patent covering the same invention as that of the defendant and interference proceedings have been taken, equity will not compel the specific perform ance of the contract to assign; Hildreth v. Thibodeau, 117 Fed. 146.
When the statute of frauds requires that a contract shall be evidenced in Writing, that will be a fourth requisite to the specific exe cution of it such case the contract must be in writing and certain in its terms; but it will not matter in what form the instrument may be, for it will be enforced even if it ap pear only in the consideration of a bond se cured by a penalty; Old Colony R. Corp. v. Evans, 6 Gray (Mass.) 25, 66 Am. Dec. 391; 2 Story, Eq. Jur. § 751. The specific per formance of a parol contract to convey land cannot be enforced if defendant urges the statute of frauds; Pitt v. Moore, 99 N. C. 85, 5 S. E. 389, 6 Am. St. Rep. 489.
Equity vvilrnot decree specific performance of an agreement to convey property which has no existence, or to which the defendant has no title; Kennedy v. Hazelton, 128 U. S.
667, 9 Sup. Ct. 202, 32 L. Ed. 576. Where the record title is defective, and parol evidence would be required to sustain it (the title not being good by the statute of limitations), spe cific performance will not be decreed ; Mc Pherson v.. Schade, 149 N. Y. 16, 43 N. E. 527. Georgia courts refuse to follow this rule in its strictness; Cowdery v. Greenlee, 126 Ga. 786, 55 S. E. 918, 8 L. R. A. (N. S.) 137, where a deed was not duly attested and was therefore not recordable.
If it appear that the want of title was known to the plaintiff when he began suit, the bill will not be retained for the assess ment of damages, but the plaintiff will be left to his remedy at law ; Kennedy v. Hazel ton, supra. A description of land in the contract sufficient to enable the vendee to find and examine it is sufficient to justi fy specific performance; Koch v. Streuter, 218 Ill. 546, 75 N. E. 1049, 2 L. R. A. (N. S.) 210. A contract to convey property which one party may at any time ac quire in the future, such party not having any property at the time of the contract, will not he enforced where the consideration is grossly inadequate to the value of the prop erty subsequently acquired; Marks v. Gates, 154 Fed. 481, 83 C. C. A. 321, 14 L. R. A. (N. S.) 317, 12 Ann. Cas. 120.
Specific performance will be granted where the defendant, having contracted to buy cer tain laud of the plaintiff, refused to perform on the ground that a widow more than sev enty years of age might have children who would be entitled to an interest in the prop erty, on the presumption that a woman of such advanced age is incapable of child-bear ing; Whitney v. Groo, 40 App. D. C. 496.
In applying the equity of specific perform ance to real estate, there are some modifica tions of legal rules, which at first sight ap pear inconsistent with them and repugnant to the maxim that equity follows the law. The modifications here referred to are those cf enforcing parol contracts relating to land, on the ground that they have been already performed in part ; of allowing time to make out a title beyond the day which the contract specifies; and of allowing a conveyance with compensation for defects; Adams, Eq. 85; Bisph. Eq. 364.