If there was any error in charging that another person, in addition to this defendant, was engaged with him in operating the automobile, in a careless and negligent manner, it was harmless error in this case. What good would it have done Peterson if Gardner's name had been eliminated from the information? While, as a general rule, an automobile is operated only by one person, it is not impossible for two persons to take part in such operation. But a joint participation in a negligent operation would be unusual to say the least. *Page 722