Defendant in error was employed by plaintiff in error as telegraph operator and clerk at its station in Huffman, Tex., on its line of railway. It was a part of his duties, for which he received extra compensation, when requested by the agent in charge of the station, to operate an engine owned by plaintiff in error and used for pumping water into a tank. Part of the machinery constituting the engine and pump was a large cogwheel about four feet in diameter, which, when the engine was in gear, was meshed with a smaller cogwheel on a revolving shaft. On the shaft and revolving with it was a clutch operated by a lever to throw the engine in or out of gear. Two links on each side of the shaft and forming a part of the clutch mechanism also revolved with the shaft, and these links, which were about six inches long, joined like a hinge, being held by pins extending through them. The pins were made to be held in place by cotter keys, hut at the time of the injury of defendant in error finishing nails about two and three-f ourtbs inches long were in the pins instead of cotter keys, and protruded out from the point where the two links came together.
When the engine was running, hut not in gear, as it was usually run when first started and until it “warmed up,” the links lay almost flat, rotating with the shaft, hut, when the engine was put in gear, the links, still *901rotating, were elevated to about a sixty-degree angle, standing out three or four inches farther from the shaft, and each pair of links forming an inverted Y, at the apex of which were the protruding nails. On account of the rapidity of the revolutions, the change in the links from the flat to the sharp position was not easily discernible. No guards were provided for the cogwheels, the shaft, or the clutch.
Defendant in error went to the pumphouse to oil the engine, stopped it, oiled it, and started it again. As he was leaving, he turned to see whether an oil cup over the cogwheel was dripping, and, not being able to see the cup from his position, walked around the shaft and stood in the L formed by the shaft and the large cogwheel. After observing that the cup was dripping, he turned to leave, when his sweater was caught by the protruding nails and wound around the shaft. This jerked him down and caused his right arm to fall into the cogwheels, which severed it above the elbow.
Defendant in error had been employed at this station for about six and a half years' and had operated the engine many times. He was a telegraph operator by trade and not a trained or experienced mechanic. Repairs necessary to be made on the pump and engine were made by plaintiff in error’s water service repairman. Defendant in error testified that at the time of his injury he did not know that the links extended farther out from the shaft when the engine was in gear, and did not know that there were nails in the pins holding the -links together.
The jury, in answer to special issues, found that plaintiff in error was negligent in allowing nails to be used in place of cotter keys for holding the links of the clutch, that it was negligent in allowing the nails to protrude in such manner that the same would catch on objects with which they came in contact, and that it was negligent in failing to warn defendant in error of the dangers that might reasonably be encountered from the revolving clutch. Judgment in favor of defendant in error for $20,000, the amount of damages assessed by the jury, was affirmed by the Court of Civil Appeals. 45 S.W.(2d) 734.
The principal.contention made by plaintiff in error is that there is no evidence of any negligence on the part of plaintiff in error in respect to any of the issues in the case. Propositions are presented' to the effect that no negligence was shown because there was no testimony that the nails were more dangerous than cotter keys or protruded farther than was necessary or farther than cotter keys’ would Jhave protruded, because there was no ■ evidence that by the exercise of care the nails' - or cotter keys could have been so arranged that they would not have caught on objects with which they came in contact, and because • there was no evidence that plaintiff in error : knew that the nails were protruding. ■■ -
The first question is whether there, is any evidence sufficient to warrant a reasonable belief that the employer failed to exercise ordinary care in furnishing reasonably safe appliances for carrying on the work. Washington v. M., K & T. Ry. Co., 90 Tex. 314, 38 S. W. 764. “To authorize the cojirt to take the question from the jury, the evi-denee must be of such character that there is no room for ordinary minds to differ as to the conclusion to be drawn from it.” Lee v. I. & G. N. R. R. Co., 89 Tex. 583, 36 S. W. 63, 65.
It is to be remembered that 'the duty . under consideration is the important nondele- : gable one imposed upon the master to ex'er^; cise care both in supplying safe and suitable appliances and in maintaining them in safe • condition, so that it shall be reasonably prob.-' able that injury will not occur in the exercise ' of the employment. Fort Worth Elevators Co. v. Russell (Tex. Sup.) 70 S.W.(2d) 397; Morton Salt Co. v. Wells (Tex. Sup.) 70 S.W. (2d) 409; Ebersole v. Sapp (Tex. Com. App.) 208 S. W. 156; Choctaw, etc., Ry. Co. v. McDade, 191 U. S. 64, 24 S. Ct. 24, 48 L. Ed. 96; Labatt’s Master and Servant (2d Ed.) §§ 917; 1009 ; 29 Texas Jurisprudence, pp. 152; 177; 18 R. C. L. pp. 587, 787. The servant, so. long as he exercises ordinary care for hi^ own _ safety, has the right to rely. upon. the. mas-⅝ ter’s performance of his duties and to- pre-, sume that the tools, appliances, and places ■ are fit and suitable. 18 R. C. L. pp. 689, 690; 29 Texas Jurisprudence, pp. 211-213 ; G., H. & S. A. Ry. Co. v. Garrett, 73. Tex. 262, 13 S. W. 62, 15 Am. St. Rep. 781; Philadelphia, etc., Ry. Co. v. Marland (C. C. A.) 239 F. 1.
Looking to the facts in the light óf these principles, we have reached the conclusion that there is evidence from which it ’ may reasonably be inferred that plaintiff in' error was negligent in the performance of its ’ duties. We do not have the ordinary case of-exposed or unguarded cogwheels, shafts, ox-other moving machinery where the danger in. coming in contact is apparent or obvious. The; dangerous instrumentality Which, caused.the; Injury is at least somewhat unusual and pe--culia-r. The .links, 'joined by a pin or bolt held; *902in place by protruding ordinary finishing nails, a makeshift, and rapidly revolving with •the shaft, stood out from the shaft in the form of an inverted V with the protruding nails at (he apex of the V, when the engine was running in gear, in such way that the links, or the points of them, were about three •or four inches farther away from the shaft than when the engine was running out of gear. The rapidity of the revolutions obscured this change in the position of the links, which rendered greater the danger in going near the revolving shaft. And this greater danger was enhanced by the presence, at the points of the rapidly revolving extended links, of protruding finishing nails where there should have been cotter keys. It is fairly to be inferred that an ordinarily prudent employer exercising reasonable care for the protection of an employee would not expose him to such hazard.
While the general rule is that the master is under no duty to protect with guards moving parts of machinery, such rule is not applicable where there are special circumstances enhancing the danger. 29 Texas Jurisprudence, p. 227, and cases cited; note 36 A. L. R. p. 1477, and following. And see 18 R. O. L. pp. 591, 592, where the statement is made that the tendency in the late cases is to hold the employer negligent in failing to guard all dangerous appliances. The danger ordinarily present in rapidly moving parts of .machinery was certainly enhanced by the peculiar construction and operation of the .¡clutch which has'been described and by the -presence of protruding nails.
As to the contention that the evidence does •jiot show that the nails protruded farther rthan cotter keys would have protruded, or ¡that cotter keys could have been arranged so -.that they would not have caught on objects •¡with which they came in contact, we think it, is reasonably concluded from the facts in evidence as to the construction and operation of the clutch that ordinary prudence would' direct an employer to use, instead of pointed protruding nails to hold the pins in place, cotter keys so short or so rounded at their ends or bent back so flat against the pins that they would not protrude for any appreciable distance and would not readily catch on objects near them.
The absence of proof as to how long the nails were in use in the clutch or by whom they were placed there does not absolve plaintiff in error, for the nails at the time of the injury were actually in use as a part of the clutch, and responsibility 'for the character and condition of the machinery rested upon plaintiff in error, not upon defendant in error. This is not a case like a number of the authorities relied upon by plaintiff in error where the cause of the injury was unexplained or where the particular thing that brought it about was not in the control of the employer but may have been the result of the act of a third person or of the injured employee himself. There is no evidence suggesting that defendant in error was in any way responsible for the use of the nails. He testified that he did not know of their presence until after he was injured. Repairs on the . machinery were made by another employee of plaintiff in error.
In the following cases the facts were very similar to those in this case, and the employers were held liable for injuries to employees: Farmers’ Cotton Oil Co. v. Barnes (Tex. Civ. App.) 134 S. W. 369 (petition'for writ of error refused); Standard Portland Cement Co. v. Foley (C. C. A.) 270 F. 203 (writ of certiorari denied 256 U. S. 693, 41 S. Ct. 534, 65 L. Ed. 1174); Longview Cotton Oil Co. v. Thurmond, 55 Tex. Civ. App. 499, 119 S. W. 130; Smith v. Queen City Lumber Co. (Tex. Civ. App.) 141 S. W. 309.
The nondelegable duty of warning an inexperienced servant of the dangers incident to his employment is also imposed upon the master. 29 Texas Jurisprudence, pp. 152, 159; 18 R. C. L. pp. 732-733. The inexperienced servant should be given full information. Missouri Pacific Ry. Co. v. Watts, 64 Tex. 568. While the master is under no obligation to caution experienced servants of dangers which are open and palpable (29 Tex. Juris, p. 159) it is his duty to warn even them-of the dangers which are latent, abnormal, or unusual. G., H. & S. A. Ry. Co. v. Garrett, 73 Tex. 262, 13 S. W. 62, 15 Am. St. Rep. 781; H. & T. C. Ry. Co. v. Malloy, 54 Tex. Civ. App. 490, 118 S. W. 721 (application for writ of error refused); Labatt’s Master and Servant (2d Ed.) '§ 1146. When the danger is hidden or unusual, the warning should be commensurate with the risk and explicit. Philadelphia, etc., Ry. Co. v. Marland (C. C. A.) 239 F. 1; Labatt’s Master and Servant (2d Ed.) § 1160.
Defendant in error was inexperienced in that he had never had any character of training that taught him about machinery or how to operate it. He was told not to oil the engine while it was running, but he was not warned of the particular, peculiar, and obscure danger in the combination of the flaring links and the protruding nails. In view of *903these facts, it is our opinion that there was evidence sufficient to warrant the submission to the jury of the issue of negligence in failing to warn defendant in error of the dangers that might be encountered from the revolving clutch.
An assignment of error presents the contention that the defense of assumed risk was raised by the evidence and should have been submitted to the jury. This defense was pleaded and is presented by the assignment under the terms of the Federal Employers’ Liability Act (45 USCA §§ 51-59). Plaintiff in error correctly states, however, in a brief recently filed, that this assignment should not be sustained, on account of a recent decision by the Supreme Court of the United States (Chicago & Eastern Illinois R. R. Co. v. Industrial Commission of Illinois, 284 U. S. 296, 52 S. Ct. 151, 76 L. Ed. 304), holding that one in similar employment was not engaged in interstate commerce.
The trial court refused to submit the following special issue requested by plaintiff in error: “Do you find from a preponderance of the evidence that the injuries sustained by plaintiff on the occasion in question did not proximately result from an accident?”
Refusal to submit this issue was not error, because it is not a correct issue. Admittedly the injury to defendant in error was the result of an accident in the ordinary or popular meaning of the word, which is “the happening of an event without the concurrence of the will of him by whose agency it was caused” (Bouvier’s Law Dictionary [3d Ed.] vol. 1, p. 101), or “an undesigned and unexpected event” (Webster). While the word “accident” is often used in the law of negligence as meaning the happening of an event without fault or neglect on the part of any one, in its ordinary meaning it does not negative the idea of negligence on the part of the person whose act brought about the event. Hogan v. Kansas City Public Service Co., 322 Mo. 1103, 19 S. W. 707, 65 A. L. R. 129; Campbell v. Jones, 73 Wash. 688, 132 P. 635; Ullman v. Chicago & N. W. Ry. Co., 112 Wis. 150, 88 N. W. 41, 56 L. R. A. 246, 88 Am. St. Rep. 949.
Since the word “accident” as used in the requested charge was not qualified or defined, the jury would have given to it its ordinary meaning, and an answer favorable to plaintiff in error would not have been a finding that the injury resulted from an unavoidable accident. An unavoidable accident can occur only in the absence of negligence. Ro-senthal Dry Goods Co. v. Hillebrandt (Tex. Com. App.) 7 S.W.(2d) 521; Dallas Ry. & Terminal Co. v. Darden (Tex. Com. App.) 38 S. W.(2d) 777; Texas Interurban Co. v. Hughes (Tex. Com. App.) 53 S.W.(2d) 448 ; 20 R. C. L. p. 17. But negligence usually consists in. the “involuntary and casual,” that is, “accidental,” doing or omission to do something, which results in an injury. Root v. Topeka Ry. Co., 96 Kan. 694, 153 P. 550.
Since a negative answer to the issue-requested would not have been a finding of unavoidable accident or of an absence of negligence, it could not have served as the basis: for a judgment in favor of plaintiff in error. For this additional reason the trial court did not err in refusing to submit the issue requested. Armour & Co. v. Tomlin (Tex. Com. App.) 60 S.W.(2d) 204.
Even if it should be held that the issue, although incorrect in the form submitted, was sufficient to direct the attention of the trial judge to unavoidable accident as a defense and to make it his duty to prepare and submit to the jury a special issue in correct form, still no error is shown, because-there was no assignment of error in the Court of Civil Appeals and there is none here complaining of the failure of _ the trial court to> prepare and submit such issue. It is held that an assignment to the effect that the court erred in refusing to submit a requested issue or charge (incorrect or defective in form) does not present complaint of the failure of the court to prepare and give an issue or charge in proper form. Wichita Falls R. & Ft. W. Ry. Co. v. Combs (Tex. Com. App.) 268 S. W. 447; Crawford v. El Paso Sash & Door Co. (Tex. Com. App.) 288 S. W. 169; Southwestern Portland Cement Co. v. McBrayer (Tex. Civ. App.) 140 S. W. 388 (application for writ of error refused).
It is unnecessary to determine whether there is evidence raising the issue of unavoidable accident.
The trial court did not err in refusing to submit to the jury a requested issue presenting the question whether defendant in error was negligent in not looking when he started to turn away from the engine, because this question was but an element of fact within the scope of, and to be determined in answering, several issues which were submitted. Such issues were, in substance: Was the injury of'defendant in error proximately caused by his. failure to exercise care in thinking about his work and the dangers he was encountering in it? Did defendant in. *904error; standing as he did in such proximity to the engine and machinery while in motion, fell' to 'exercise ordinary care to keep himself and his clothing a safe distance therefrom? Was he negligent in permitting a part of his áweater to become caught in the rapidly moving; machinery? Was the injury proximately caused by his failure to take reasonable care fro'keóp himself and his clothing a safe distance from the moving parts? Was he negligent in talking the position he.did while the engine was in operation in attempting to de-. termine whether the oil cup was dripping?
An expert machinist testifying for defendant in error described in detail the clutch mechanism, the links, and the manner in which the links lay almost flat when the engine was not in gear but protruded when it was in gear. He testified that, when the engine was running in gear, the links appeared nearly transparent- like they were almost straight. He was askp.d whether, but for his knowledge and experience in operating ma-chh)e,i;y, he would have been able to detect tile change in the links from the flat to the protruding position .when the engine was in operation. Plaintiff in error’s objection that thof..question failed, for the conclusion of the, witness .was. overruled., and the .witness answered-: “I would'notice it, I would be expecting it, but if. I did not have mechanical experience I would not have 'looked for it.”
>-Plaintiff in error takes the position that by this; answer the witness usurped the province of, the- jury because he in effect gave testimony that the protruding of the links when the engine was running in gear would not he apparent to a person having no mechanical experience:
The answer objected to is, we think, when it is read in connection with the other testimony of the witness, descriptive of the machinery rather than expressive of a conclusion or opinion. It. told the jury, if the meaning ascribed to it by plaintiff in error is correct, that the protruding position of the links was, by reason of the rapidity of the revolutions, so indistinct that it would not be observed by one who for want of experience Would not be expecting it, and so would not he looking for it. ■ The answer gave the jury information about the appearance of the moving- machinery that could not have been imparted clearly by mere literal description.
If it is regarded the expression of an opinion, it is the opinion of an expert given in connection with a detailed description of r ‘ the facts upon which it is based. Even'the' Opinions of nonexperts are sometimes admissible.
“The opinion of a common observer may he received where the facts upon which it is based are incapable of being presented or explained to others with their proper force or significance, * * *. In other words, whenever a condition of things is such that it cannot be reproduced and made palpable to a jury, or when language is not adequate to such realization, a witness may describe it by its effect upon his mind, even though such effect be opinion.” 19 Tex. Juris, pp. 19, 20. See, also, M., K. & T. Ry. Co. v. Gilerease (Tex. Civ. App.) 187 S. W. 714 (application for writ of error refused); McCabe v. San Antonio Traction Co., 39 Tex. Civ. App. 614, 88 S. W. 387 (application for writ of error refused).
The answer objected to was not in fact the expression of an opinion that one without mechanical experience would not observe the protruding position of the links. The witness did not even testify that he would not have observed it but for his experience. He merely stated that if he had been inexperienced he would not have .looked for it.
The trial court did not err in overruling the objection to the question.
The assignments of error attacking the findings of the jury in answer to special issues submitting several phases of contributory .negligence, on the ground that the findings ale contrary to the great weight and preponderance of the evidence, do not present questions within the jurisdiction of the Supreme Court. Parks v. San Antonio Traction. Co., 100 Tex. 222, 94 S. W. 331, 98 S. W. 1100; Ellis v. Brooks, 101 Tex. 591, 102 S. W. 94, 103 S. W. 1196; Texas Power Corporation v. Kuehler (Tex. Com. App.) 52 S.W.(2d) 76; Damon v. State (Tex. Com. App.) 52 S.W.(2d) 368.
The same is true as to the assignment of error that the verdict is excessive. International & Great Northern R. R. Co. v. Goswick, 98 Tex. 477, 85 S. W. 785; Wilson v. Freeman, 108 Tex. 121, 185 S. W. 993, Ann. Cas. 1918D, 1203; Burrell Engineering & Construction Co. v. Grisier, 111 Tex. 477, 240 S. W. 899; Galveston, H. & S. A. Ry. Co. v. Leifeste (Tex. Com. App.) 22 S.W.(2d) 1061.
The judgment of the trial court and that of the Court of Civil Appeals are affirmed.
Opinion adopted by the Supreme Court.