delivered the opinion of the court.
1. The cause was apparently tried upon the theory that there was an issue raised by the pleadings as to whether the wire which caused' the injury to plaintiff was placed in a position before the trestle upon which plaintiff was at work was erected. The most casual reading of the pleadings wiE show at once that there was not any issue upon this question at all. The complaint in paragraph Y above, in plain and unmistakable language, charges that the defendants on or about the 1st day of May, 1902, hung this wire, charged with an electric current of two thousand five hundred volts, over and above and across a trestle at the East Colusa mine. The denial of those allegations is, that any of the defendants, except the Butte Electric and Power Company, hung the wire mentioned in the complaint over and above or across the trestle at the East Colusa mine; and that any of the defendants hung the wire mentioned in the complaint only three feet or about three feet above said trestle. The answer alleges that a certain wire hung by. the Butte Electric and Power Company was so hung over and above said trestle, a distance of about four and one-half feet from said trestle, and was called a secondary wire. These pregnant denials admit that the Butte Electric and Power Company strung the wire mentioned in the complaint, charged with an electric current of two thousand five hundred volts, over the trestle at the East Colusa mine. The only denial is that such wire was only three feet or about three feet above the trestle.
*280If the trestle was not there before the wire was placed in position, it is hardly necessary to say that the wire could not have been strung over and across the trestle, and therefore the answer unmistakably admits the existence of the trestle before the wire which caused plaintiff’s injury was placed in position.
The particular wire which caused the injury is definitely identified in the proof as a primary wire; so that the trial court would have been justified in stating to the jury that there was not any issue upon the question, but that the answer admits that this wire with which plaintiff came in contact was placed in position after the trestle upon which he was working was erected* But the defendants offered proof tending to show that there were four wires stretched over this trestle; that two of them were primary and two secondary wires; that the primary wires were charged with an electric current of from two thousand to two thousand five hundred volts, while the secondary wires were charged with only about one hundred and four volts, which was not sufficient to have caused the injury complained of.
Acting upon the assumption that there was an issue as to whether the wire or the trestle was first put in place, the court submitted to the jury certain instructions of which complaint is made. One of these instructions (No. 9) was asked by the defendants and given by the court with a material modification. By this instruction the jury were told that if they found from the evidence that the wire which caused the injury to plaintiff was strung by the defendants before the trestle was erected; that the trestle was erected by a third person without the knowledge or consent of the defendants, and was not used by the defendants, and that plaintiff was at work on the trestle for some person other than the defendants; and that the defendants did not know that the trestle was being used; and if they further found that the wire which caused the injury was strung a sufficient height above the surface of the ground to render it impossible for persons at work or traveling in that vicinity to come in contact with it by ordinary means, then *281the act of plaintiff in coming in contact with the wire was contributory negligence on his part which would preclude his recovery. To this extent the instruction was asked by the defendants, but the court attached to it this modification: “Unless you find that the said defendants were guilty of negligence in not inspecting their property at such reasonable periods of time as would enable them to know and discover that said trestle had been erected under their said wires and was being used as a passageway by human beings, and that the erection of said trestle had brought the said wires so close to persons passing across said trestle as to be dangerous to the lives and safety of human beings. ’ ’
The court, by instruction No. 12, told the jury that if they should find from the evidence that the wire which caused the injury was strung before the trestle was erected, then they were instructed that it is the duty of persons or corporations transmitting electric currents that are dangerous to human safety or life, to inspect their properties at reasonable intervals with a view of ascertaining what, if any, physical changes have taken place which might create or increase danger to human life ; and in this ease, if the jury should find that the property was not inspected at reasonable intervals, and that a reasonable inspection would have disclosed the existence of the trestle and the physical conditions surrounding it at the time the plaintiff was injured, then, in that event, the defendants were charged with knowledge of the existence of the trestle.
Objection is made to instruction No. 9 as modified, and to No. 12, in that they impose upon the defendants the duty of inspecting their lines of wire, even if the trestle was erected after the wire which caused the injury was strung. Appellants contend that if it was found that the trestle was erected after the Mure was put in place, then, as to the defendants, the plaintiff was a naked trespasser, and, as to him, the defendants did not owe the duty of inspection, and in support, of this cite Egan v. Montana Central Ry. Co. et al., 24 Mont. 569, 63 Pac. 832, Beinhorn v. Griswold, 27 Mont. 79, 94 Am. St. Rep. 818, 69 *282Pac. 557, 59 L. R. A. 771, and Driscoll v. Clark, 32 Mont. 172, 80 Pac. 373. Bnt the complaint alleges that the plaintiff was rightfully and lawfully in pursuit of his business at the time when, and place where, he was injured, and this is not denied. Neither is there anything in the pleadings or proof which would even tend to show that the owner of the trestle was, as to the owner of the wire, a trespasser.
The wire was strung on and along a public street, and the trestle was built across the street at right angles with the course of the line of wire. As said before, the answer specifically admits that the wire was strung after the trestle was erected; but if it be said that all parties proceeded in the trial court upon the theory that there was an issue raised as to this fact, still there is not anything which would justify the conclusion that either the owner of the wire, or the owner of the trestle was, as to the other, a trespasser. The law will not presume it, but, in the absence of any showing to the contrary, the presumption is that each alike was there lawfully. So that we may at once dismiss from our consideration any contention that the owner of the trestle was a trespasser; and this being so, the cases cited above from this state are not in point here. Defendants’ liability to the plaintiff must, therefore, be determined by rules applicable to one injured by the alleged negligence of another, where the injured party was rightfully pursuing his business or pleasure at the time of his injury.
In 3 Current Law, 1182, the rule as to this liability is announced as follows: “While one furnishing electricity is not an insurer, yet as to the public he is obliged to use the utmost human care, vigilance, and foresight, reasonably consistent with the practical operation of his plant, to provide against all reasonably probable contingencies, the care required in any particular case being proportional to the danger. This includes the use of the best mechanical contrivances and inventions in practical use, perfect insulation at all places near which people have a right to go, and it has been held, perfect insulation of all overhead wires strung through streets, the consideration of climatic *283conditions, and the maintenance of such a system of inspection as will insure reasonable promptness in the detection of defects.”
While this rule goes farther than it is necessary for us to go in this instance, we do adopt and approve it to the extent that it holds the owner or operator of an electric plant to a reasonable degree of care in erecting pole lines, selecting appliances, insulating the wires wherever people have a right to go and are liable to come in contact with them, and in maintaining a system of inspection by which any change which has occurred in the physical conditions surrounding the plant, poles or lines of wire, which would tend to create or increase the danger to persons lawfully in pursuit of their business or pleasure, may be reasonably discovered. (Mitchell v. Charleston L. & P. Co., 45 S. C. 146, 22 S. E. 767, 31 L. R. A. 577.)
Other courts announce the rule in even stronger terms. For instance, in Colorado, it is said: “Moreover the court in other instructions correctly declared that the defendant was bound to exercise the highest skill, most consummate care and caution, and utmost diligence and foresight in the construction, maintenance, and timely inspection of its entire plant which was attainable, consistent with the practical conduct of its business according to the best known methods of the state of its art at and prior to the time of the disaster.” (Denver Con. Electric Co. v. Lawrence, 31 Colo. 301, 73 Pac. 39.)
And in Pennsylvania the rule respecting the duty of a gas company is stated as follows: “While no absolute standard of duty in dealing with such agencies can be prescribed, it is safe- to say in general terms that every reasonable precaution suggested by experience and the known dangers of the subject ought to be taken. This would require in the case of a gas company, not only that its pipes and fittings should be of such material and workmanship, and laid in the ground with such skill and care, as to provide against the escape of gas therefrom when new, but that such system of inspection should be maintained as would insure reasonable promptness in the detection of all leaks that might occur from the deterioration of the material *284of the pipes, or from any other canse within the circumspection of men of ordinary skill in the business. ’ ’ (Koelsch v. Philadelphia Co., 152 Pa. St. 355, 34 Am. St. Rep. 653, 25 Atl. 522, 18 L. R. A. 759.)
It would hardly do to say that the defendant can only be required to exercise due diligence after it receives notice of any defect in its appliances or of any change in the physical conditions surrounding them, for this would be placing a premium upon negligent ignorance, as was said, in substance, by the supreme court of South Carolina in Mitchell v. Charleston L. & P. Co. above. (District of Columbia v. Woodbury, 136 U. S. 463, 10 Sup. Ct. 990, 34 L. Ed. 472.)
Under the rule which we have announced above, we think the court’s instructions No. 9 as modified, and No. 12 as given, correctly state the law.
2. The court also gave an instruction, numbered 5, of which complaint is made. That instruction is as follows: “The court instructs the jury, that all persons or corporations who handle a force of great inherent danger to - the lives and safety of others, are held by law to a high degree of care in handling the same, to the end that other persons shall not be hurt by the same, while such other persons are not trespassing and are rightfully minding their own business; in other words, the care required is measured by and equal to the danger; when anyone handles a force of utmost danger, a very great care is required; what would be care in handling a force of little danger might not be care in handling a force of great danger and might be negligence in handling such a force; as the danger increases, so th§ degree of care increases which is required of persons who are handling the force; the degree of care required is proportionate to the danger of the force, and where a force of highest danger is handled, a very high degree of care is required in handling the said force to the end that no other person lawfully minding his own business and not trespassing may be hurt by the force.” We think this instruction correctly states the law.
*285In Commonwealth Electric Co. v. Melville, 210 Ill. 70, 70 N. E. 1052, it is said: “Electricity is a subtle and powerful agent. Ordinary care exercised by those who make a business of using it for profit to prevent injury to others therefrom, requires much greater precaution in its use than where the element used is of less dangerous character. As there is greater danger and hazard in the use of electricity, there must be a corresponding exercise of skill and attention for the purpose of avoiding injury to another, to constitute what the law terms ‘ordinary care.7 The care must be commensurate with the danger.77 .
In Hoye v. Chicago M. & St. P. Ry. Co., 46 Minn. 269, 48 N. W. 1117, the Minnesota court states the rule as follows: “Reasonable care is all that is required. But this must be proportionate to the risks to be apprehended and guarded against.77 This language is quoted with approval by the same court in the later case of Gilbert v. Duluth Gen. E. Co., 93 Minn. 99, 106 Am. St. Rep. 430, 100 N. W. 653.
The same rule in practically the same terms is announced by other courts and text-writers as follows: “It would have been safer and the better practice to instruct the jury — which ought hereafter to be observed — even in cases like the one before us, that the defendant was bound to exercise that reasonable care and caution which would be exercised by a reasonably prudent and cautious person under the same or similar circumstances. In addition to this, the jury should have been instructed that the care increases as the danger does, and that, where the business in question is attended with great peril to the public, the care to be exercised by the person conducting the business is commensurate with the increased danger.77 (Denver Con. Electric Co. v. Simpson, 21 Colo. 371, 41 Pac. 499, 31 L. R. A. 566.)
“An electric light company is bound as to the public exercise the utmost degree of care in the construction, inspection, repair and operation of its apparatus and appliances; or, disregarding distinctions as to degrees of care, the rule may be thus stated: To prevent an injury to the public, the law requires that usual *286and ordinary care should be used, which, in such a business as an electric light company operates, requires and demands a degree of care and diligence proportionate to the danger or mischief that is liable to ensue. The words ‘usual and ordinary care’ mean in such cases nothing more or less than that if there be great danger and hazard in the business, there should be a corresponding degree of skill and attention required by the law.” (10 Am. & Eng. Ency. of Law, 872.)
“Electric companies are bound to use ‘reasonable care in the construction and maintenance of their lines and apparatus— that is, such care as a reasonable man would use under the circumstances — and will be responsible for any conduct falling short of this standard.’ This care varies with the danger which will be incurred by negligence. In cases where the wires carry a strong and dangerous current of electricity, and the result of negligence might be exposure to death or most serious accidents, the highest degree of care is required.” (City Electric St. Ry. Co. v. Conery, 61 Ark. 381, 54 Am. St. Rep. 262, 33 S. W. 426, 31 L. R. A. 570.)
“The measure or degree of care required of electrical companies is variously defined, but it is conceived that the consensus of opinion is that they must exercise that reasonable care consistent with the practical operation of their business which would be observed by reasonably prudent persons under like circumstances, increasing the care with any change in conditions likely to increase the danger, and having due regard to the existing state of science and of the art in question.” (15 Cye. 472.)
Many of the cases growing out of alleged negligence by companies handling electricity are reviewed in Keasbey on Electric Wires, sections 242-255, and the doctrine announced is that embodied in instruction No. 5. After all is said, the instruction only announces the familiar rule in negligence, cases, that the defendant is required to exercise reasonable care. But what is reasonable care in handling brick and mortar may amount to criminal negligence in handling nitroglycerin; so that the only *287rational rule is that announced by the trial court: that the care required is measured by and equal to the danger.
3. By instruction No. 10 the court told the jury that there was not any evidence which would warrant the jury in finding that the defendants had actual notice of the erection of the trestle, and that their wires had been brought in close proximity to it; but that the jury should only consider this in the event that they believed from the evidence that the wire which caused the injury was hung before the trestle was erected; and in the event they believed from the evidence that the wire was strung after the trestle was erected, then the defendants were chargeable with knowledge of the existence of the trestle and the physical conditions surrounding it. If there was any error in this instruction, it was error in the defendant’s favor.
4. Upon the trial the plaintiff offered testimony which tended to show that he had lived in Butte about seventeen or eighteen years; that he had worked in and about the mines and reduction works in Silver Bow, Deer Lodge and Granite counties; that he had received from three to four dollars per day, according to the character of work he did; that among others he had worked for-one D. H. Dunshee for six or seven years; that in 1901 he was at work in the Pennsylvania mine and worked there for about a year. He was then asked what wages he received there. This question was objected to on the ground that the investigation should be limited to an inquiry as to the wages he was receiving at the time the accident occurred, and that the testimony was irrelevant, incompetent and immaterial. The objection was overruled and error is assigned to this ruling of the court.
We think the objection was properly overruled. It might have occurred that at the time of the injury the plaintiff was not receiving any wages at all, and had not been for some time prior thereto, and, while it would have been competent for this fact to have been made to appear to the jury, it can hardly be said that an injured party under such circumstances would not be entitled to recover anything. Section 4330 of the Civil *288Code establishes the measure of damages in cases of this kind, as follows: “For the breach of an obligation not arising from contract, the measure of damages, except where otherwise expressly provided by this Code, is the amount which will compensate for all detriment proximately caused thereby, whether it could have been anticipated or not. ’ ’
In a leading English case upon this subject it is held, that where recovery was sought by a physician for injuries which occasioned loss of time and which impaired his capacity to earn money in the future, the jury might consider proof of the average aggregate of yearly fees received by the physician before his injury. (Phillips v. London etc. R. R. Co., L. R. 5 Q. B. 78, 42 L. T., N. S., 6; Patterson’s Railway Accident Law, secs. 393-396.) We do not think that the period of time covered by the inquiry in this instance was unreasonable.
5. In the specifications of errors in appellants’ brief, under the head “Insufficiency of Evidence to Justify the Verdict,” it Is stated that the evidence is insufficient to justify a verdict for $20,000, the amount returned by the jury; but counsel apparently attached little importance to this contention, as their brief-does not contain any argument whatever upon the subject. Kennon v. Gilmer et al., 9 Mont. 108, 22 Pac. 448, and Hamilton v. Great Falls St. Ry. Co., 17 Mont. 334, 42 Pac. 860, 43 Pac. 713, are cited, but to what purpose is not just apparent. In each of these cases the verdict was apparently arbitrarily scaled. Fulsome v. Concord, 46 Vt. 135, and Houston H. & T. C. R. Co. v. Willie, 53 Tex. 318, 37 Am. Rep. 756, are the only other cases cited, and these likewise without any argument or comment whatever.
In Fulsome v. Concord the trial court reminded the jury that an allowance for prospective damages is making payment in advance, and in fixing upon a sum for such damages this fact might be taken into consideration and the amount reduced to its present worth. On appeal the supreme court said of this: “As the effect of this suggestion would be to lessen the damages, if it had any effect,' the defendant cannot complain of it, and we *289find no legal error in it. In respect to the amount of prospective damages to be awarded, the jury are the exclusive judges. ’ ’
In Houston etc. Co. v. Willie, the supreme court of Texas said that compensation for lessened ability to earn money should be made upon the principle that the amount allowed is such as will purchase an annuity equal to the difference between the injured party’s annual earnings before his injury, and the amount, if any, he might earn thereafter.
But if these eases are cited in support of some contention which appellants may make, that the jury was improperly instructed upon the method to be employed in determining the amount of damages for impairment of earning capacity in the future, it is sufficient to say that a more definite instruction than that given by the court, was not asked by them. The court instructed the jury that if they found for the plaintiff, then in fixing the amount of damages they might take into consideration mental and physical pain and suffering caused by the injury; wages which plaintiff might have earned from the date of the injury to the date of the trial; and, finally, if they found that the injuries are permanent, they might take into consideration any loss to him by reason of the impairment of his capacity to earn money in the future. No complaint is made of this instruction and none could well be made. We are, however, of the opinion that an instruction particularly informing the jury of the plan or standard to be adopted in estimating damages for impairment of capacity to earn money in the future should be given in all such cases; but, if defendants desired a more specific instruction than that given, they should have asked for it.
We think the rule announced by the Texas court, above, is the correct one, and in fact the only safe guide in fixing such damages. The question in a case of that kind is: What amount will purchase an annuity equal to the difference between the annual wages or salary received-by the plaintiff before and after the injury, where the injury is the proximate cause of the im*290pairment of earning capacity? This rule is approved in Baltimore & Ohio R. Co. v. Henthorne, 73 Fed. 634, 19 C. C. A. 623; 4 Sutherland on Damages, 3d ed., sec. 1249.
The law does not contemplate that the injured party shall be paid in advance a sum, the interest from which will equal such amount and at his death leave the principal to his estate, but only that he shall not be made to lose because of his injury. From standard mortuary tables and tables made use of by actuaries to determine the cost of a particular annuity, such damages may be ascertained and fixed with some degree of certainty.
However, the elements of physical and mental pain and suffering are entirely uncertain and no fixed standard can be established for ascertaining the damages occasioned by them. The amount must, of necessity, rest in the sound discretion of the jury, and courts are ever reluctant to interfere with the verdict upon the ground that it is excessive or insufficient. The parties are entitled to a verdict from the jury, and courts ought not to substitute their judgments for those of juries, except in those exceptional cases where it manifestly appears that the jurors made a mistake in calculation, considered an item or items of damages which should not have been considered, or abused that sound discretion which by the law is vested in them.
From the testimony given in this case the jury might properly have drawn the conclusion that the plaintiff’s earning capacity was totally destroyed by this accident, and that his mental faculties as well were greatly impaired by reason of it.
Had the jury been instructed as to the proper standard for estimating damages for impairment of capacity to earn money in the future, they might, by a reasonable, but not excessive, allowance for mental and physical pain and suffering, have arrived at the amount fixed by their verdict. In any event, the burden of showing error rests upon the appellants, and in the absence of a clear showing, this court would not be justified in interfering upon the ground of excessive damages alone, particularly where, as in this instance, the evidence is such that the jury might well have drawn the conclusion that plaintiff’s *291injuries are permanent. (13 Cye. 130, and numerous cases cited.)
Rehearing denied December 19, 1905.We have considered the other assignments, but find no error.
The judgment and order are affirmed.
Affirmed.
Mr. Chief Justice Brantly and Mr. Justice Milburn concur.