Stockbridge, J.,

delivered the opinion of the Court.

This Court is now called upon, for the first time, to apply in an action to recover for personal injury the provisions of the Act of Congress of April 22nd, 1908, Chap; 149, entitled “An Act Relating to the Liability of Common Carriers by Railroad to Their Employees in Certain Oases.” The special importance lies in the fact that under that Act the established rules of the common law with regard to' contributory negli *423 gence, negligence of a fellow-servant and. assumption of risk were radically modified.

The ease presented brings up' for review the rulings of the trial Court upon demurrers to the declaration, forty-six exceptions reserved to the admission or rejection of evidence, and one to the action of the Court upon the prayers. It will not be necessary, however, to consider each one of these in detail, four of the bills of exception, the fifth, seventeenth, fortieth and forty-third, having been abandoned by the counsel for the appellant in his brief, and the large proportion of the others will he sufficiently dealt with in an expression of the, views of this Court upon the Act in question, as applied to this particular case.

The important facts in the case are as follows: Harvey W. C. Whitacre had been for several years an employee of the Baltimore and Ohio Eailroad Company as a brakeman, and at the time of the happening of the accident in question, June 23rd, 1913, was what is known as front brakeman on a freight train, having a run from Cumberland, in the State of Maryland, to the Cumbo Yards, near Martinsburg, in the State of West Virginia. The railroad was at the time a common carrier, engaged in doing interstate business, and the employment of Whitacre was in the conduct of interstate business. On the morning of the day named, Whitacre was called about 1 o’clock, with orders to join a train in his capacity of brakeman, which was to leave Cumberland at 2 o’clock. In response to that call, at or about the appointed time, he reported at the caller’s office, and then proceeded through the yard of the railroad company to join the engine, which was to he coupled to the train at the Evitts Creek Yard, some half-mile distant. The locomotive was then standing upon a “ready track,” and as the brakeman approached it he did not see the engineer hut did see the fireman, and Whitacre put on his working clothes. He then inquired of the fireman whether he was ready to start, and he received the answer, “Ho, not quite.” “The tool hoy had *424 not been there and had left him no tin cup, and he asked me to go and hunt the tool boy and get a tin cup.” This is the testimony of the plaintiff himself. The fireman’s version differs somewhat. Acting upon what the plaintiff understood to be the order or request of the fireman, he did start to look for the tool boy and tin cup, and saw at a little distance a moving light, which he followed, supposing it to be a lantern in the hands of the tool boy. Suddenly the light disappeared around some object, subsequently ascertained to be an engine. The plaintiff then took a few steps backward and fell into a cinder pit, -which was near the center of the yard, and used for the purpose of raking the cinders into from the firepan of the locomotive. This cinder pit was of large size, approximately 180 feet in length by 50 feet in breadth, and varying in depth from 3% to 9 feet. It was of recent construction, having been in use but about six months, and was what is known as a water pit as. distinguished from a dry pit. There was no railing around the pit, but at or near the center it was spanned by iron or steel beams, upon which was worked a travelling crane, that was used in the daytime for the removal of cinders from the pit. The allegations contained in the declaration, and borne out in the testimony, were to the effect that it had been raining; that the night was somewhat thick and foggy, and that the top of the water in the pit was covered to a greater or less extent with ashes, which made it difficult, if not impossible to distinguish it in appearance from solid ground. When the plaintiff fell into the pit he was wetted up to- his waist, and fell across an iron bar or rail, but clambered out, returned to his engine without the tin cup, and the engine proceeded to the Evitts Creek Yard, where it was attached to the cars to be hauled to the Gumbo Yard. The plaintiff performed a portion, if not all, of his regular duties as brakeman, which involved getting down and coupling and uncoupling the air pipes between the tender of the engine and the front freight car. This operation was repeated several times between *425 Cumberland anti the Cumbo Yard. He did, however, while ■on the trip complain of his accident to the conductor of the train, and an accident report was made out at Hansrote, one of the intermediate stations. From the Gumbo Yard the plaintiff returned to Cumberland on a passenger train. The following day ho consulted a physician, who after examining him found a rupture for which an operation was performed, and from which ho recovered. After some months the plaintiff complained of pain in his spine, for which he was treated by applying a white hot iron; and still later there developed what was claimed to he a fracture of the bone of the thigh containing the socket, with which the head of the femur articulates. These are in substance the injuries to recover for which the suit was brought. Some others were set out in the •declaration, but not substantiated by the proof.

The declaration in its various counts charges negligence, negligence in the omission to supply the tin cup, negligence in the construction and maintenance of the cinder pit, and inferentially negligence in allowing the ashes deposited in the cinder pit, or some portion of them, to obey the laws of gravitation, and iloat on the top of the water.

The grounds upon which liability is denied by the defense are, absence of negligence upon the part of the railroad company, both as to the tin cup and the construction of the pit; secondly, that the risk, if risk there was, was one assumed by the plaintiff when he entered upon the employment, and it was further urged that in leaving the engine and going to look for the tool hoy, the plaintiff was doing an act not materially or directly connected with interstate commerce, and that, therefore, the Act of Congress had no application.

The first question to be answered is as to the applicability of the Act of Congress. It is difficult to reconcile the various decisions, even to reconcile those of the same Court. A few propositions, however, are clear. These are, that the Act was intended to apply only in certain cases, thus recognizing that there was a class of cases which might arise between a *426 common carrier by railroad and its employees, in which the Act had no applicability. This was distinctly recognized in the case of the Illinois Central R. R. Co. v. Behrens, 233 U. S. 473, in an opinion by Justice Van de Vanter, and is further emphasized by section 1 of the Act: “This clause has two branches; the one covering the negligence of the officers, agents or employees of the carrier * * *, and the other relating to the defects and insufficiencies in the cars, engines, appliances, etc.” But plainly with respect to the latter, as well as the former ground of liability, it was the intention of Congress to base the action on negligence only, and to exclude responsibility of the carrier to its employees for defects and insufficiencies not attributable to negligence * * To hold that under the statute the railroad company’s liability for the injury or death of an employee resulting from any defects or insufficiencies of its cars, engines, appliances, etc., however caused, is to take from the Act the words “due to its negligence.” The plain effect of these words is to condition the liability upon negligence.” And in any given case the measure of the responsibility of the carrier is that of ordinary care. Seaboard Air Line v. Horton, 233 U. S. 501.

The argument and brief of the railroad company devoted much attention to the question of primary negligence; but under the wording of the Act this contention can not be held sound; if there was any act of negligence upon the part of the railroad company, then even though there was contributory negligence upon the part of the plaintiff, or of a fellow servant, and the plaintiff was, at the time of the happening of the accident, engaged in interstate commerce, and there had been no assumption of the risk upon his part, then the Act must be held to apply.

That the plaintiff must be regarded as being engaged in interstate commerce at the time of the happening of the accident seems conclusively settled by two cases. In the P., B. & W. R. R. Co. v. Tucker, 35 App. D. C. 123, subsequently *427 affirmed per curiam by the Supreme Court, Tucker was killed by being struck by an engine when he was on the premises of the defendant, in response to its call to assume the duties-he had been engaged by the defendant to assume for their mutual interest and advantage; and it was there laid down that the obligation of the master commences when the servant, in pursuance of his contract with the master, is rightfully and necessarily upon the premises of the master. In the No. Car. R. R. v. Zachary, 232 U. S. 248, it was held that the acts of an employee in preparing an engine for a trip to move freight in interstate commerce, although done prior to the actual coupling-up of the interstate cars, are acts done while engaged in interstate commerce. In this latter case the party for whose death the action was brought was a fireman on a locomotive of the Southern Railway, he had prepared his engine for the trip and was crossing the railroad yard from Ms engine to go to his boarding-house; and had passed behind one locomotive, when he was run down by a switching engine on an adjoining track. Certainly the act of the fireman in going to his boarding-house was no more an act connected with interstate commerce than was the act of Whitacre in hunting for a tool hoy in order to obtain a tin cup for the use of the crew on its trip.

An endeavor was made in the evidence to predicate the-act of negligence of the company upon the failure of the-tool hoy to supply the locomotive with a cup, an attempt which was but partially successful as it was not satisfactorily shown that the tin cup was an absolute essential to the movement of the train, which in fact did move without it, and the evidence of the fireman tended rather to show that even if it had been present, its use, according to individual taste, might have been dispensed with in favor of the lid of the water cooler.

In the prayers which, were offered at the conclusion of the-case, the tin cup as a negligent omission on the part of the company seems to have been lost sight of, and the negligent *428 .act relied on, at this stage, appears to have been the method of construction and maintenance pf the cinder pit. There was a practical unanimity of evidence that the pit itself was .admirably constructed according to the best modern engineering ideas of what such a pit should be, but the negligence claimed was of two descriptions: one, the insufficient lighting ■of the pit, in regard to which there was a conflict of evidence whether the electric lights which had been placed there were or were not burning at the time of the happening of the ■accident, so' as to> give a good illumination of the pit; and, .second, .that the pit was a dangerous appliance for the purpose for which it was designed and used, by reason of the absence •of guard rails. Upon this phase also there was a conflict •of evidence, that of the plaintiff in support of the dangerous character of the appliance, being the testimony of certain engineers in the nature of what is commonly spoken of as •expert testimony.

Some of the exceptions to evidence go to the admissibility •of this testimony, upon the theory that the dangerous character vel non of the pit as constructed without guard rails, •and with water upon which the lighter portion of the ashes might float, was a matter so within the common, every-day knowledge of the average citizen that expert evidence was inadmissible. With that contention this Court can not agree; the construction of railroad cinder pits is not a matter with which the average individual is so brought in contact in his daily life as to be necessarily familiar with what is and what is not practicable and proper, as to exclude evidence of an expert character. Furthermore, it appears that only a very small number of water pits have been built thus far in this country. How they may compare with dry pits in the element of danger is known to but few and is clearly without the range of the ordinary experience of the individual. It was., therefore, proper to admit this evidence, as was done, and there was thus raised by the testimony a distinct issue. *429 as to the negligence of the defendant, the railroad company,, in the construction and maintenance of the pit.

Hid the plaintiff, Mr. Whitacre, assume this risk? The rule -has been frequently laid down, both in this State and elsewhere, upon this subject, and is well stated in the case of Wood v. Heiges, 83 Md. 257, that a person assumes all risk of all dangers which are open and obvious, but not dangerous which arise from the negligence of the master, unless after knowledge of such danger the servant continues with full knowledge to perform his work. The rule was given its fullest application in the Seaboard Air Line R. R. v. Horton, 233 U. S. 492, where the guard glass over the boiler gauge in the cab of a locomotive was missing, and was reported as missing by the engineer to his superior seven or eight days before the happening of the accident, and though the missing guard glass was not supplied, the engineer continued to run his engine, and was injured by the bursting of the gauge, and the engineer was held, by continuing to work without the replacement of the guard glass, to have assumed the risk incident to its absence. And a similar case is that of Byers v. The Coal Co., 230 Pa. 10; although in this latter case the Act of Congress was in no way involved. See also So. Ry. Co. v. Crockett, 234 U. S. 730. In the case under consideration the plaintiff had been into the Cumberland Yard in connection with his work on a number of occasions; certainly once at night, and knew or must have known of the existence there of the cinder pit; but the performance of his duties was not at the cinder pit, nor was he necessarily placed in the position with relation to it where he must be construed by law to have known whether it was a dangerous appliance or not, and he had the right to assume, that as constructed it was a proper and safe appliance. Upon this branch of the case the Act of Congress has no application, because section 4, by its terms, applies only in a certain class of cases, of which this is not one, and if we take the rules as applied in the State Courts, the risks which are assumed by an employee *430 .are those incident to, .or connected with, -the work which the employées perform, not those which may exist in other portions of the establishment or yard where he himself has no duties and where he has the right to rely upon the master’s having performed his entire duty. In the case of McCann v. Alt. Mills, 20 R. I. 566, relied upon by the appellant, and which is the case most nearly approaching this in its facts, the Court did say that, “It was the duty of the employer to furnish his employees drinking water, but the fact that it was not so furnished does not warrant the plaintiff in wandering about the yard in the darkness in search of it, at any one’s risk except his own;” the Court, however, in deciding the case places its decision not upon the assumption of risk, but of the contributory negligence of the plaintiff. So in this case, the act of the plaintiff in going about the yard as he did, was one to be viewed rather as contributory negligence than an assumption of risk, and that aspect of the case was fully .and properly covered by the plaintiff’s third prayer.

From what has been said, it follows, that no. reversible -error is found in the rulings of the trial Court upon the demurrer to the declaration, or the 1st, 2nd, 3rd, 4th, 9th, 10th, 18th, 19th, 20th, 21st, 22nd, 25th, 27th, 30th, 31st, 32nd, 33rd, 34th, 35th,, 36th, 37th, 38th, 39th, 42nd and 46th exceptions to- evidence. The 7th exception was to permitting the plaintiff to testify with regard to promotions in the service; at best the question was immaterial, and no injury ■’has been pointed out or is apparent from the admission of that evidence by the Court.

The eighth exception was to the exclusion upon cross-examination of the plaintiff of the question, whether his wife had died of tuberculosis. This was also immaterial to- 'any issue raised in the case.

The eleventh and twelfth exceptions were taken to-the admission by the Court of the evidence of an insurance expert, in giving from his tables the value of an income, such as the ■plaintiff was receiving at the time of the accident. This evi *431 deuce was. of course intended as a guide for the jury in determining the proper amount of damages, to he awarded. AYithout some evidence in regard to this before the jury, there was no basis except vague speculation on which to base any verdict. The insurance tables of expectancy, based upon actual experience of the large life insurance companies, while not conclusive, have been recognized to he the best character of evidence obtainable for such purposes, and the evidence objected to by these two exceptions was properly admitted.

This is quite different from the objection raised in the 44th exception where the Court refused to permit a physician to express his opinion upon the prospect of the life of the plaintiff; there had been nothing to show upon what any such opinion might he formed, whether it was the result of professional observation from long years of continuous practice, or upon the occupation of the plaintiff, or what circumstances he might or might not have considered in reaching his opinion, and the Court acted properly in excluding his evidence.

The 13th, 14th, 15th and 16th exceptions all related to the taking of an X-ray photograph of the hip hone, which was claimed to have been fractured, whether the angle at which taken would or would not tend to disclose or conceal any such fracture. Evidence had been given by physicians of the fact of fracture, discovered by manipulation, hut the use of photography in cases of this character is now so universally recognized, that it is properly regarded as evidence of the strongest sort in any such case, and yet, as is well known the lights or shadows produced by the angle of light may make a material difference in the appearance; it was, therefore, entirely proper that the witness should he fully examined upon this point. There were a number of other exceptions to evidence, and while with regard to some of them the correctness of the ruling of the Court is not as clear, none of them disclose such injury to the plaintiff as to justify a reversal.

*432 The last exception was to the rulings of the Court upon the prayers; of these three were offered on the part of the plaintiff, and seventeen upon the part of the defendant.

The plaintiff’s first prayer, submitted to the jury, in the form in which it was modified by the Court, the question of the negligence-of the railroad company, and as modified when taken in connection with the defendant’s tenth prayer, fully placed before the jury the issue of negligence upon the part of 'the defendant as an essential element to the recovery, and is not open to the criticism suggested by the defendant.

The plaintiff’s second prayer was the customery prayer as to the measure of damages, and the third prayer was upon the apportionment of damages between the plaintiff and defendant, with respect to the finding of the jury as to negligence and contributory negligence, in strict accordance with the Act of Congress. While this prayer is a new one in this State, yet it seems to have been drawn with peculiar care, and is not open to objection.

The first and third prayers of the defendant were prayers to take from the jury. But since there was some evidence tending to show negligence on the part of the Railroad Company they were properly rejected. The defendant’s fourth prayer was to the effect, that if the pit in question was constructed in a similar manner to those constructed by other railroad companies, that then the jury could not find any negligence in its construction. This was manifestly a bad prayer. The Court was not concerned with the question whether other railroads were or were not negligent in their appliances, but whether the Baltimore and Ohio was, and the mere fact that the mode of construction followed that done by another company, and which may or may not have 'been a safe and proper appliance, could form no basis to relieve the Baltimore and Ohio Company from liability in case the jury found negligence in the construction and maintenance of this pit.

The defendant’s fifth prayer was granted with a modification ; but what that modification was is not indicated in the *433 record, and the reading of the prayer does not disclose anything in it which could operate to the disadvantage of the defendant.

The defendant’s sixth, seventh, eighth, ninth and eleventh prayers have been sufficiently covered by what was said in the general discussion of the case and need not be further considered.

The defendant’s twelfth prayer was properly rejected because the tenth prayer, which had been granted with modifications, sufficiently covered the same matter, and the granting of it would have tended to confuse the jury.

The thirteenth, fourteenth and sixteenth prayers of the defendant all involve a construction by the jury of the rules of the company, and therefore were properly refused, such construction being a matter for the Court and not for the jury.

The seventeenth prayer of the defendant was based in part upon certain rules of the company which had been offered in evidence and subsequently withdrawn, and being withdrawn from evidence no prayer could properly be granted, -which involved a consideration of that which was not in the case.

Finding no reversible error, the judgment appealed from will be affirmed.

Judgment affirmed, with costs.