It is manifest that the bill in this case, in its entire scope and purpose, is a bill to compel the specific performance by the defendant of certain contracts between him and the complainant. By those contracts the defendant undertook to produce and construct, by his labor, skill and inventive genius, certain improved machinery for manufacturing speaking tubes. Said machines, as the bill alleges, were to embrace and embody various new and useful improvements and inventions made and to be made by the defendant. No details or specifications are given in the contracts as to the form, materia], structure, principle or mode of operation of the proposed machines, all of these- matters being left wholly to the judgment and discretion of the defendant. Indeed, it is difficult to see how it would have been possible to give any specifications and details of the machines, as some, and perhaps many of them, had as yet no existence in the minds of the contracting parties, but were to be invented and developed by the defendant by means of subsequent thought, study and experiment.
There are at least two insuperable reasons why these contracts can not be specifically enforced in equity. The first isj *57that courts of chancery will not entertain bills to compel the specific performance of contracts for personal services. Especially is this true where the services stipulated for require the exercise of mechanical skill, intellectual ability and the exercise of judgment. Although some cases may be found in the earlier reports holding a contrary doctrine, the rule as we have stated it, is now well settled. Among the various applications of the rule to be found in the reports, the following may be noticed. In Baldwin v. The Society for the Diffusion of Useful Knowledge, 9 Simons, 393, by agreement between the plaintiffs and defendant, the former, in consideration of certain payments to be made to them by the latter, were to have the exclusive right of engraving and publishing a series of maps and drawings to be furnished to them, from time to time, by the latter. The court refused to restrain the defendant from acting in violation of the agreement, as it could not compel the defendant to furnish the drawings, and therefore, could not decree a specific performance of the agreement. In Clark v. Price, 2 J. Wils. Ch. 157, the court refused to decree the specific performance of a contract, by which the defendant agreed to compose and write reports of cases argued and determined in the Court of Exchequer, to be ¡published by the plaintiff. In pronouncing the decision the Lord Chancellor said: “ The only means of enforcing the execution of this agreement, would be to make an order compelling Mr. Price to write reports for the plaintiff, which I have not the means of doing. If there be any remedy in this case, it is at law.” The same rule is applied to an agreement by a person to act at a theater. Kemble v. Kean, 6 Simons, 333; Lumley v. Wagner, 1 DeGex, Mc. & G. 604; Hamblin v. Dinneford, 2 Edwards’ Ch. 529. In the case.last cited the court says: “The difficulty is, how to compel specific performance. The court can not oblige the defendant to go to the theater and there perform particular characters. Imprisonment for contempt would be the consequence of his refusal, and this would defeat the performance sought to be enforced.” See also, Ford v. Germon, 6 Phila. 6.
*58In Stocker v. Wedderburn, 3 Kay & John. 393, the plaintiff, being the owner of certain letters patent, entered into a written agreement with other persons to form a joint stock company, for the purpose of working the patents, he agreeing on his part to sell the patents to the company on certain terms, and take all requisite measures for obtaining patents in foreign countries, and to give his whole services to the company for two years, and to do his best to improve the invention, and to impart such improvements to the company, and it was held that the plaintiff could not obtain specific performance of this agreement against his co-promoters, because, from the nature of his own part of the agreement, the court could not compel specific performance of it by him. See also Webb v. England, 29 Beavan, 44, where the rule above stated is held to apply to a contract to work as an apprentice, or to instruct asa master; and Booth v. Pollard, 4 Y. & C. 61, where it is applied to a contract to work quarries or coal mines.
Another rule applicable to the specific performance of contracts to which courts of equity have uniformly adhered is, that a bill for that purpose will not be maintained unless the contract-sought to be enforced is certain and definite in its terms and in all its parts. Shenandoah Valley R. R. Co. v. Lewis, 76 Va. 833; Schmeling v. Kriesel, 45 Wis. 325; Nichols v. Williams, 22 N. J. Eq. 63; Colson v. Thompson, 2 Wheat. 336 ; Los Angeles, etc., Association v. Phillips, 56 Cal. 539; Bowman v. Cunningham, 78 Ill. 48; 1 Story’s Eq. Juris. § 767; Fry on Specific Performance, § 317 et seq., and authorities cited.
The foregoing rule, especially in its application to a case like the present, is so well stated and discussed in Blanchard v. D. L. & L. M. R. R. Co., 31 Mich. 43, that we feel justified in quoting at length the following language from the opinion of the court: “ The jurisdiction of equity in specific performance proceeds on the supposition that the parties have not only agreed, as between themselves, upon every material matter, but that the matters so agreed on are of such a nature, and the subjects of enforcement so delineated or indicated, *59either directly or by reference to something else, or so raised to view by legitimate implication, that the court can and may collect, and in their proper relations, all the essential elements, and proceed intelligently and practically in carrying into execution the very things agreed on and standing to be performed. If, however, it appears, either that the things to he performed are in their nature incapable of execution by the court, or that needful specifications are omitted, or that-material matters are left by the parties so obscure or undefined, or so in want of details, or that the subjects of the agreement are so conflicting or incongruous, that the court can not say whether or not the minds of the parties met upon all essential particulars, or if they did, they can not say cxact’y upon what substantial terms they agreed, or trace out any practical line where their minds met, the case is not one for specific performance. As the court does not make contracts for parties, so it never undertakes to supply material ingredients which they omit to mention, and which can not he legitimately considered as having been within their mutual contemplation. And where the party to perform is left by the agreement with an absolute discretion respecting material and substantial details, and these are therefore indeterminate and unincorporated until by his election they are developed, identified and fixed as constituents of the transaction, the court can not substitute its own discretion, and so by its own act perfect and round out the contract.”
If a court of equity should attempt to order a specific execution of the contract in this case, it is manifest that insurmountable obstacles would immediately present themselves. It would be impossible for the court to specify or describe in its decree the machines to be constructed, their form, material or structure, or if it attempted to lay its mandate upon the defendant to proceed with the invention and construction of the machine stipulated for, it could never know with certainty whether its order was obeyed. If it should attempt to take the execution of the contract into its own hands, it would be met with equal difficulties. Its officer charged with the performance of its decree would be powerless. The court would *60thus find itself unable either to compel the defendant to execute the contract, or to cause it to be executed through any of the agencies by means of which courts of chancery ordinarily enforce their decrees.
It is urged, however, by the counsel for the complainant, that a portion of the relief sought, viz., that the defendant be required to show and exhibit to the complainant the plans and •drawings of said machines heretofore prepared by him, and make disclosure and discovery to him of the principle and structure of the machines already built, is not in, the nature of decreeing a specific performance of the contracts, and therefore does not come within the principles above discussed. In this we think counsel are mistaken. This particular measure of relief, with which it is now suggested that they may be content, seems to us clearly to be nothing Jess than a partial execution of the contracts. The defendant’s under, taking was not merely to construct and deliver to the complainant certain machines, but .to .embody in such machines various improvements and inventions already made and yet to be made by him. Obviously the principal thing sought by the complainant and secured to him by the contracts was the defendant’s improveménts and inventions. The mere construction of the two machines after their invention had been achieved, was quite secondary and relatively of little importance. . These improvements and inventions were to be assigned and transferred to the complainant, and such transfer and assignment involved, as a necessary and principal element, a complete disclosure and discoyery to him of the principle and structure of the machines, so as to enable him to avail himself of said inventions and discoveries. Compelling the defendant to make the disclosure and discovery asked for, and to place in the complainant’s hands the plans and drawings of the machines, would be giving him all the substantial and really valuable benefits of the contracts, and would be for all substantial and valuable purposes a specific execution of the contracts.
We do not perceive that the case is at all changed by the fact averred in the bill that the complainant, on being shown *61the plans and drawings prepared by the defendant, approved and was satisfied with the machines which they purported to represent, and so informed the defendant. While, by the terms of the contracts, the complainant was not bound to pay the defendant the stipulated price until he approved, accepted and was satisfied with the machines, the question after all is, whether the machines built or partially built by the defendant, and of which he prepared plans and drawings, were really and in fact the machines contemplated by the contracts; for, if they -^ere not, the plaintiff’s approval imposed upon the defendant no obligation to deliver them to. him. So far as the bill shows, those machines, when completed, may have proved failures equally with the first one built, which did not seem to work. Unless they were capable of operating in the manner and of producing the results stipulated for, they can not be held to be the machines contemplated by the contracts, and the complainant had no right to claim them.
If, therefore, the court had undertaken to compel the defendant to make discovery of the principle and structure of the machines built, it would still have been uncertain whether the improvements and inventions thus disclosed were the ones contemplated by the contract. Under such circumstances a specific performance will never be awarded.
We are of the opinion that the demurrer to the bill was properly sustained, and the decree will therefore be affirmed.
Decree affirmed.