Those are four separate petitions for writs of prohibition.- Tbe petitioners are all foreign manufacturing corporations and were joined as defendants with a large number of other foreign and domestic corporations in an action brought in tbe circuit court for Milwaukee county by tbe Yelie Motor Vehicle Company, a foreign corporation, •charging conspiracy to ruin its business and alleging damage to tbe amount of $500,000. Tbe summons and complaint in •said action were attempted to be served on tbe petitioners by service upon certain persons and domestic corporations alleged to be agents of tbe respective petitioners transacting business for them in this state. Tbe petitioners separately moved in tbe circuit court,® upon affidavits showing tbe con“tract relations between themselves respectively and tbe alleged agents upon whom service was attempted to be made, *285for orders setting aside tbe service in eacb case upon tbe ground tbat tbe persons and corporations upon whom service-was made were not agents of tbe petitioners witbin tbe meaning of tbe statute. These motions were denied, and tbe petitioners now ask tbis court to exercise -its power of superintending control and issue writs of prohibition to tbe circuit court and its judge, commanding tbat no further proceedings be taken in tbat action and tbat tbe motions to set aside tbe attempted service be granted.
Tbe power of “a general superintending control over all inferior courts” which tbe constitution (art. VII, sec. 3) grants to tbis court was first extensively considered and its limits defined in tbe case of State ex rel. Fourth Nat. Bank v. Johnson, 103 Wis. 591, 79 N. W. 1081. Tbe subject has-been discussed in a number of cases since tbat time, but no attempt has been made either to vary or enlarge tbe general principles laid down in tbe first named case, but, on tbe other band, in all of tbe subsequent eases those principles have been either literally or in substance approved and applied.
Those principles in substance are tbat tbis jurisdiction is not to be exercised upon light occasion, but only upon some grave exigency; tbat tbe writs by which it is exercised will not be used to perform tbe ordinary functions of an appeal or writ of error; tbat tbe duty of tbe court below must be plain; its refusal to proceed witbin tbe line of such duty or, on the other band, its intent to proceed in violation of such duty must be clear; tbe results must be not only prejudicial but must involve extraordinary hardship; tbe remedy by appeal or writ of error must be utterly inadequate; and tbe application for the exercise of the power of superintending control must be speedy and prompt. State ex rel. Fourth Nat. Bank v. Johnson, supra; State ex rel. Milwaukee E. R. & L. Co. v. Circuit Court, 133 Wis. 442, 113 N. W. 722; State ex rel. Milwaukee v. Ludwig, 106 Wis. 226, 82 N. W. 158; State ex rel. Umbreit v. Helms, 136 Wis. 432, 118 N. W. 158.
*286Does the present case come within these principles ? We think not. One of the cardinal rules is that the duty of the ■court below must be plain. The situation must be such that hardly more than a statement of the facts is necessary to convince the- legal mind as to the duty of the court. Where there is no such clear and obvious duty based either upon common-law principles or upon express statute, but where questions of law or fact, or both, are involved of such difficulty that “a judge may reasonably, proceeding considerately, commit judicial error,” the court will refuse to intervene under its power of superintending control, but will leave the parties to their remedy by appeal. State ex rel. Milwaukee E. R. & L. Co. v. Circuit Court, 134 Wis. 301, 114 N. W. 455. The duty of the court cannot be said to be plain in the present case: difficult questions were presented to the trial court upon the motions to vacate the service; questions in the solving of which there was ample room for the ablest trial judge, after mature consideration, to commit error.
The complaint alleged conspiracy to ruin the plaintiff’s business. One of the principal overt acts of this conspiracy from which great damage is alleged to have resulted is charged to have been committed in the state of Wisconsin. The damages caused by the overt acts in pursuance of the conspiracy form the gist of the action, hence it would seem that a substantial part at least of the cause of action arose within this ■state. In a case where the cause of action arises within this state service may bo made upon the agent of a foreign corporation “having charge of or conducting any business therefor in this state.” Subd. 13, sec. 2631, Stats. (1898). The ■affidavits submitted upon the motions to vacate the service disclosed that all of the persons and corporations served on as agents were purchasing automobiles of their respective principals and selling the same under long written contracts prescribing prices, time of payment, territory in which to sell, and many other things. The contracts are very carefully *287drawn and do not use tbe word agent, but it is a very serious question, to say tbe least, whether agencies in fact are not created by all of them. We do not now say that such agencies were created, but simply that tbe question is not one that can be answered with confidence at once either way. It is worthy the considerate and careful attention of any court and may well admit of different opinions by equally able legal minds. One of the conditions essential to the successful invoking of the power of superintending control is therefore wanting.
It is urged that the case is one of such exceptional hardship that this court should intervene and stop the proceedings in the court below notwithstanding the duty may not be plain. The argument runs thus: The order denying the motion to vacate the service is not appealable, nor can it be reviewed on appeal from final judgment if the defendants appear and defend the case on the merits, because by such appearance they waive the question of jurisdiction (Corbett v. Physicians’ C. Asso. 135 Wis. 505, 115 N. W. 365); hence they can only raise the question 'by staying out of court, allowing judgment by default for an immense- sum perhaps to be taken against them, which judgment will stand as a menace to their credit for months until they can bring their appeal to a hearing.
The argument is not without its weight, but we cannot admit its conclusiveness. Logically followed out, it would mean that in every case where large damages are claimed this •court may be called upon to investigate and decide any question as to the sufficiency of the service of the summons before another forward step is taken in the trial court. The result would be that mandamus, prohibition, and procedendo would gradually but surely be used to perform the ordinary functions of an appeal, which this court has- declared is not the proper function of those writs.
By the Court — Motion denied in each ease with $10 costs.