WiNslow, J.

When the defendant’s agent, Diebler, requested the plaintiff to assist him in the work of putting the binder upon the trucks, and the plaintiff consented to do so, the plaintiff became for the time being defendant’s servant *51to all intents and purposes, and a co-employee of the defendant with Diebler, entitled to the same protection as any other servant of the defendant of similar age and intelligence, and subject to the same risks of injury from the negligence of a fellow-servant. Johnson v. Ashland W. Co. 71 Wis. 553; S. C. 77 Wis. 51. If there was serious danger and hazard in the work, which was not obvious, and which a boy of plaintiff’s age and intelligence would not be expected to know, then he was entitled to be warned of such danger, and the failure of Diebler to so warn him would constitute negligence on the part of the defendant; for in this respect Diebler was undoubtedly a vice principal. If, however, there was no failure of duty in this respect, the subsequent failure of Diebler to properly block the machine would be simply the negligence of a co-employee, for which the defendant would not be responsible. Klochinski v. Shores L. Co. 93 Wis. 417.

The question to be decided, therefore, is simply whether the danger of the machine falling over was such a danger as called for a warning on the part of Diebler before he set the plaintiff at work.

Upon this question, it seems to us that the answer must dearly be in the negative. The placing of a binder upon its trucks is an operation of a similar character to many operations which are continually going on upon a farm, and in which boys of the age of the plaintiff are frequently called upon to assist. The danger of the machine falling over, if not properly blocked up, was patent to a boy of this age as well as to a man. There is, of course, danger in any operation involving the lifting and moving of heavy articles which may lose their equilibrium, but this danger is one within the common knowledge of boys as well as men. It would not be reasonable to hold that a boy must be warned that a heavy article may fall and hurt him, if not properly supported, every time he is asked to assist in moving it. *52Warning is not required against obvious dangers in ordinary-operations which are matters of common knowledge to all. Bailey, Personal Injuries, § 2730. The boy received an unfortunate and serious injury, but we are unable to see that the defendant is responsible for it upon any principle of law.

By the Court. — -Judgment affirmed.