BARTOH, J.,
after stating tbe case as above, delivered the opinion of tbe court.
The appellant contends, inter alia, that the court erred in charging the jury as follows: “An employee of a railroad company assumes the ordinary risks incident to bis employment (but bis employer has no right by any act of bis to so increase those risks, without warning the employee, as to make the employment more dangerous than the employee would naturally expect; and if the employer does so act as to increase the hazard assumed by him, and by reason thereof, through no fault of bis own, the employee is injured, the employer is 1 liable).” We are of the opinion that this portion of the charge is objectionable. A perusal of it seems to create the impression that the court assumed that the employer increased the ordinary risks incident to the employment without warning the employee thereof. At least the language and construction of the sentence are such as were likely to cause the jury to consider increase of risks as a fact regardless of whether it was shown to be such by the evidence. The instruction omits entirely every element of knowledge on the part of the employee of any practice of the defendant to act in such a way, and fails to state that if the employee knew that such was the practice be assumed the risk as an incident to the business. It makes the employer liable for the increase of the ordinary risks incident to the employment because of the per*238formance of a particular act, although it may have been the custom and practice of the employer to perform such acts in the conduct of the business, and such custom and practice may have been known to the employee. The court was also unfortunate in the use of the word “naturally” instead of “reasonably.” The question is not whether the risks of the 2 employment were more dangerous than- the employee would naturally expect, but whether they were more dangerous than he would reasonably expect. We can not say that, such a statement of the law, under the evidence in this case, did not mislead the jury and was not prejudicial to the appellant.
It is also insisted, and, we think, correctly so, that the court erred in that part of its charge included in paragraph 16, which reads: “The risks assumed by an employee are such as are necessarily incident to his employment, and do not include the unnecessary use by the employer of extraordinary instrumentalities for accomplishing his purposes, which, by their use, increase the risks and dangers ordinarily attendant upon the duties of such employee, unless it .was the practice of such employer to use such extraordinary instrumentalities, and that such practice was known, or ought to have been known, by the employee.” Here the word “unnecessary” 3 is employed in such a way that it may have led the jury to conclude that the application of the air for the purpose of stopping the train at Uintah was wrongful and unjustifiable, whether such conclusion was warranted by the proof or not. The reasonable inference would be that such application of the air must not be made except in case af absolute necessity therefor. Such a rule would render practically useless the modern equipments of railway trains, and doubtless would greatly interfere with the transaction of railroad business. We do not conceive such to be the law. A conductor of a railway train may stop his train by a proper application of air whenever a reasonable necessity for using such means exists.
*239Tbe appellant further complains of the part of the charge contained in paragraph 19, which reads: “If yon find from the evidence that the accident which caused the death of Henry E. Ohlenkamp was proximately occasioned by the negligent act of the conductor of the train (or by an act which was unnecessary, and which made the duties of the deceased more dangerous than they would ordinarily have been), and that he had no warning of such negligent or unnecessary act, then the defendant company is liable, although you may further find that other causes may also have contributed to bring about the disastrous result.” This instruction was so 4 clearly erroneous and misleading to the jury that comment respecting it would seem to be unnecessary. Here the jury was informed that, if the death of the deceased was proximately occasioned “by an act which was unnecessary,” etc., without previous warning having been given to the employee, then the railroad company would be liable, and this even though other causes may have “contributed to bring about the disastrous result.” It will be noticed that in this connection nothing was said as to whose unnecessary act would render the company liable. This was left to inference, and the rule thus declared would render the company liable in damages, as appears from the last clause of the instruction, notwithstanding that the death might have been shown to have been occasioned by contributory negligence on the part of the deceased. No such instruction can be upheld.
Other portions of the charge are susceptible of criticism, but we do not deem further reference or discussion in relation thereto necessary, except to say that a charge of a court to a •jury should be as concise as possible, since too great prolixity in many instances serves rather to confuse than to aid the jury. We are also of the opinion that the court erred in 5 admitting, over the objections of the defendant, the evidence relating to the coupling where the train separated, and to the cars being “thrown up — tipped up — off the track.” *240There was no issue presented by the pleadings that the coupling appliances were defective, or that the cars were tipped up or thrown from the track. Such evidence constituted a variance from the allegations of the complaint, and was inconsistent with the testimony of the plaintiff’s own witnesses, which showed that the coupling was not defective, and that the cars remained on the track. “The law is well, settled that a plaintiff can not declare on one theory and recover on another. It is a well-established rule of evidence that the testimony offered must correspond with the allegations of the complaint, and not show an entirely different state of facts.” Peay v. Salt Lake City, 11 Utah 331, 338, 40 Pac. 206, 207; Dan Hartog v. Tibbitts, 1 Utah 328.
There are still other questions presented, but, as a new trial must be granted, further discussion is not considered necessary.
The case must be reversed, with costs, and remanded to the court below, with directions to grant a new trial. It is so ordered.
MINER, C. J., and BASKIN, J., concur'.