Timi-IN, J.
The plaintiff in this case had a verdict which may be abbreviated as finding: (1) That he was burned by molten iron falling from a crane ladle in defendant’s foundry on May 15, 1907. (2) The apparatus controlling the movement of the crane ladle containing this molten iron was so worn and loose as not to be reasonably safe, etc. (3) This unsafe condition of said apparatus was the proximate cause of the injury to plaintiff. (4) The defendant knew of such un-safety in time to> have prevented the injury by the exercise of' ordinary care. ( 5 ) The defendant also ought to have known, *247etc. (6) The plaintiff did not know prior to the injury that said apparatus was not reasonably safe; (1) nor ought be to have so known in the exercise of ordinary care. (8) No want of ordinary care on the part of Frank Miller, a co-employ ee, caused the injury. (9) No want of ordinary care on the part of the plaintiff. (10) Plaintiff’s damages, $2,000.
The appellant’s counsel assigns numerous errors in the proceedings below, making his principal argument, however, on the proposition that the testimony on the part of the plaintiff relating to the manner in which his injury was inflicted is in contradiction of known physical laws and therefore impossible and incredible. This proposition must be supported by demonstration, not by mere conflict of evidence, and in order to present it properly all the necessary data for demonstration must appear affirmatively and not depend upon mere credibility of other witnesses. Rasmussen v. Wis. T., L., H. & P. Co. 133 Wis. 205, 113 N. W. 453. The evidence in this case is very deficient in measurements and descriptions, but, supplying defects in the testimony from an exhibit purporting to be drawn to a uniform scale and weighing the facts thus ascertained for the purpose of testing this question, we have the following:
The crane ladle in questiowwas a somewhat circular iron bucket lined with fire brick and forty-three inches in height, having an inside diameter at a point three inches below the top of thirty-nine inches, an inside diameter at the bottom of thirtydive inches, and an inside diameter near the center at the point of suspension of thirty-seven inches. It was suspended on a movable crane by means of a chain hook engaging at the apex of an arched handle somewhat similar to that of an ordinary pail or bucket. This handle arched over the top and extended on the outside down the sides of the ladle or bucket, and connected with the latter by means of two journals protruding from the ladle and carried at exactly opposite points in its circumference. Each of these journals fitted *248into journal boxes or sockets in tbe lower ends of this handle. Tbe center line of suspension of this ladle or bucket in tbe lower extremities of said handle by means of said journals was twenty-one inches above tbe bottom of the ladle and twenty-two inches below the extreme top thereof. On the occasion in question the ladle was filled to within three or four inches of the top with melted iron. The ladle has a capacity of five tons of this melted iron, as we understand the evidence. Whether this was three or four inches below the top^ would be of paramount importance in any attempt at demonstration. We have no evidence showing, when the ladle is empty, the relative mass above and below the line of suspension. The diameter of the ladle increases toward the top, and there is one inch more in height of the ladle above the line of suspension, but there is the closed heavy lined bottom as against the open top. The top carries a lip or spout over which the metal pours, but the protrusion or projection or the dimensions of this lip or spout are not given. The lining of fire brick or fire clay which covers the inside of the bottom and sides thins off in a curve at the top and the measurements of this curve are not given. This lip and curve materially affect the tilting of the ladle by bringing the molten material farther off from the line of suspension as this heavy bottom affects it in a contrary direction by rising to and remaining at a distance from the line of suspension, while the liquid contents seek their level and flow away from the bottom. But from data collected from the drawings it is apparent that, assuming the ladle to be exactly circular and of the varying diameter stated, the cubic contents of the ladle, when filled to within three inches of the top, would be 23,604 inches above and 19,330 inches below the line of suspension. This would leave about fifty-five per cent, of the whole contents above the line of suspension. Without knowing what mass of the ladle itself was above and what below this line, the last figures are not available for purposes of demonstration.
*249One of the journals on which this ladle was swung extended through its socket or journal box in the lower extremity of the handle several inches. Upon this projection there was attached rigidly a cogwheel of about twenty inches diameter equipped on its periphery with worm cogs convex on their outer edge. On top of this twenty-inch wheel and tangent to its circumference and engaging with its cogs was a straight short bar carrying a spiral projection, which for convenience we will call the “screw.” This screw was journaled at each end in journal boxes or sockets rigid upon the outside of the handle. On one end of this screw was a miter gear, and on a short shaft running at right angles with this screw and engaging with it at this end there was also a miter gear, and on the other or outside end of this short shaft was a hand wheel of about two. feet in diameter. Eor the purpose of pouring-out the molten contents of the ladle! the operator, by turning this hand wheel, imparted through the miter gearing a slow rotary motion to the screw. This last more slowly moved the rigid twenty-inch wheel, this tipping the ladle in the required direction and also holding it back from tipping over too rapidly. The spiral projection, or in other words the thread of the screw, did not fit closely between the cogs of the twenty-inch wheel, so that when the operator at the two-foot wheel began the operation of pouring out the melted iron, the ladle being then perpendicular or it might be slightly inclined in the opposite direction, he must first, by putting the screw in motion, bring the thread hard against that side of the cogs of the twenty-inch wheel opposite to the direction in which he intended to pour. This pressure would continue on that side of the cogs until the ladle had been so far tilted that the center of gravity of the ladle and its contents would‘fall on that side of the line of suspension toward which the pouring took place. At this point the ladle and its contents would take what the witnesses call a drop. That is, it would lurch in the said direction, changing the pressure of the screw thread against the *250cogs of the twenty-inch wheel to the other side of such cogs, and holding bade instead of pushing on these cogs. This, would continue until so much of the contents had been poured out that the relative quantity remaining in the bottom of the ladle with the heavy bottom would again shift the center of gravity to the other side of the line of suspension, when the ladle would take a similar lurch but in the opposite direction from the first, and the operator would be again engaged as he began.
The defendant’s witnesses agree with those of the plaintiff with respect to. the existence of these two lurches, but plaintiff’s witnesses say there were other intervening lurches, while this last is said to be impossible. Whether or not this is possible is not necessary to- the determination of this case. It depends, however, upon many factors not shown by the evidence, principal among which is the rate at which the ladle is-emptied and the continuity of the motion of tilting in one direction and the volume of bucket and contents above and that below the line of suspension and the oscillations of the swinging ladle. The extent of this lurch or drop is a matter upon which the evidence is widely divergent. There is competent evidence from both sides that the space between cogs on the-twenty-inch wheel minus the thickness of the screw thread or spiral projection amounted to one eighth of an inch. The distance from the center of suspension to this contact as-shown by the drawings is ten inches. The distance from the same center to the top of the bucket and ladle along the same line from the same data is twenty-two inches. Regarding the center of suspension as the center of a circle and the top of tire ladle in its circumference, the mathematical formula would be: cos. : sin. — r. : tan.; or 10 : .125=22 : .215. From-this cause alone the movement at the top of the ladle would be only slightly in excess of one fourth of an inch in a straight line. There is, however, in the record some testimony from the witness Gaertner in which he states that the distance from *251the point of contact between the screw and the twenty-inch wheel to the trunion of the ladle is only nine and one-half inches and the distance from this trunion to the lip or spout of the ladle or bucket presumably along the-.same line is 33-inches. Erom this he gets the proportion 9-g :-¿=33 : 7-16.. But his basic figures conflict with the dimensions' shown on the exhibit, and his proportion is not mathematically accurate. This witness further testifies that although there was only one eighth of an inch play between the cogs on the twenty-inch wheel and the spiral projection on the screw,'yet, on account of some looseness in the journals, the whole movement at this point which he found was really one fourth of an inch. Here we find an omission in the evidence which forbids any accuracy approaching demonstration. There is no- evidence-from which we can ascertain the lateral movement of the screw in its journal boxes. Nothing to show what collars or shoulders it had, how near they were to the journal boxes on-each side of the latter, and nothing to show the amount of play or looseness of the suspensory journals in the lower extremities of the handle. Consequently when an eyewitness states-that the ladle lurched or dropped several inches, while we may suspect exaggeration, we cannot demonstrate his incorrectness. The total of looseness or play estimated by Gaertner would make the lurch at the top of the ladle, according to the scale of the exhibit, 10 : .25=22 : .55, and according to Gaertner’s-data, 9.5 : .25=33 : .86 plus. In either case there would be a considerable jar from a mass of five tons suspended as described falling this distance and then suddenly arrested. It must also be considered that this lurch or movement is in a circle around the line of suspension, passing through the lower extremities of the ladle handle. The top of the ladle lurches in the direction in which the iron is being poured, while the bottom of the ladle lurches back 'in the opposite direction. The impact is against the handle at the point where the journals of the screw are rigid thereon, and this handle is loose *252at the chain book above the point of impact and at the line of suspension below the point of impact. There must therefore be at times a lurch of this swinging bucket much greater than the measurements above given. This would necessarily produce a wave and probably more than one wave of some height in the liquid iron moving in the direction in which the iron was being poured, and suddenly increasing the volume falling -over the lip or spout of the ladle. Some of the witnesses describe this lurch or drop as much greater than above indicated. We are unable to oppose mathematical verities or kinetic laws 'to the testimony of Gaertner or to that of the other witnesses, because we are left without any certain or reliable data upon which to base our computations. But it is argued that this lurch in the direction in which the iron was being poured •could.not have occurred more than once in the operation of pouring and that at or near the time when the pouring began. We find no sufficient data upon which counsel can affirm this .as a mathematical verity, although it seems quite probable. But, as said, this presents an immaterial issue. Although the plaintiff testified in examination before trial that the lurch and consequent spilling over of iron which caused his injury occurred after a considerable quantity of the contents- of the ladle had been poured out, his testimony in chief at the trial, as well as that of the witnesses Kaiser, Brember, and Schu-macher, tends to show that the lurch, spill over, and injury to the plaintiff occurred immediately after the operator began to pour. This was a question for the jury, and if they were satisfied that the accident occurred at this stage of pouring, as we must presume they were if that is necessary to uphold their verdict, all conclusions based upon other premises vanish. We are satisfied there was in the particulars covered a fair •question for the jury. It is suggested that common sense is sufficient to show the incredibility or impossibility of plaintiff’s testimony. What is thought to be common sense is frequently nothing more than a fixed belief based on no evidence *253and supported by no reasons, and it then ordinarily lacks the certainty requisite for tbe annihilation of positive evidence to-the contrary.
The defendant asked the court to instruct the jury as follows:
“If you find that in furnishing the crane ladle in use at the time plaintiff was injured defendant exercised ordinary care to see that such ladle was in a reasonably safe condition- — that is to sa.y, in substantially as safe condition as similar ladles were, which were used in such foundries generally, — then the-defendant discharged its duty toward the plaintiff, and your answer to the second question will be ‘Nod ”
This instruction is too absolute, and if given would takeaway from the jury their right to reject the test of common usage on the ground that such appliance in common use was-itself inherently, and to the master obviously, dangerous. Yazdzewski v. Barker, 131 Wis. 494, 111 N. W. 689.
There is no rule of law which will enable a master to escape-the consequences of failing to exercise ordinary care to furnish his servants reasonably safe appliances by proving that all other masters in the same line of business and using the-same appliances are equally negligent. The evidence referred to in this requested instruction was competent and proper to-be considered by the jury as bearing upon the question of' whether or not the master exercised ordinary care in this respect; but to make such evidence conclusive on the jury by an instruction like that requested here would be to bind them-to find that the other foundrymen- were men of ordinary care and prudence in this respect. This might or might not be-true. It was for the jury to say which. There is considerable testimony tending to show that the device in question is inherently and obviously defective for the purpose for which it is used when it becomes worn to such an extent as to cause- or aggravate the lurch and splash described.
On the question of assumption of -risk by the plaintiff the *254uase is quite close. There is, however, some evidence on the part of the plaintiff that he did not know of such lurch of the bucket or ladle or of the looseness of the pouring device and had no information concerning these matters; that prior to the day of his injury he had never caught in'his hand ladle melted iron from the five-ton ladle; and the jury found his lack of knowledge in this regard by the sixth and seventh questions of the special verdict. The appellant contends that this was a ■case in which the question of the contributory negligence of the plaintiff and that of his assumption of the risk should have been separately submitted, as indicated in Campshure v. Standard Mfg. Co. 137 Wis. 155, 118 N. W. 633. We believe this view is correct. The appellant, however, did not properly request the submission of such question to the jury. He asked the court to submit:
“Was the spilling of melted iron which caused plaintiff’s injuries a common occurrence in the business of molding, and •one incident to plaintiff’s work as a bench molder in defendant’s foundry ?”
If we eliminate the words “which caused plaintiff’s injuries” or treat them as equivalent to “such as caused plaintiff’s injuries,” still the question would cover only one of the •elements of assumption'of risk, viz., that of the ordinary and usual nature of the occurrence, and would leave the case with•out finding whether the plaintiff knew or ought in the exercise of ordinary care to have known of such occurrences. The ■special verdict, on the other hand, did negative knowledge of this danger, actual or imputable, on the part of the plaintiff, thus in legal effect negativing assumption of risk. If the appellant seeks in such case to assign error for refusal to submit ■a question to the jury, he must first present a proper question fully covering the matter which he wishes to have submitted.
We do not think there was error in permitting the examina- . tion of Niedermeyer as an adverse witness nor in the admission of evidence, unless it be in the opinions of the witness • -Gaerfiner with respect to. how much the gearing was worn two *255.years before. Tbis last should have been excluded because tbe witness bad no data upon ;which to base such an opinion. There is no uniformity of progress in such things. But the -evidence was not prejudicial in view of the fact that it was -contended on the part of the defendant that such gearings are always loose and necessarily loose, and that this burning of workmen with melted iron and this dip or lurch of the ladle is a common occurrence. But we are not convinced from the evidence that such gearings are always loose or necessarily loose to the extent that a lurch and a splash dangerous to workmen is usual or inevitable. If such condition, indeed, V ’ * ? prevail, a little ingenuity on the part of foundrymen will make these appliances safe, take them out of the category of inherently dangerous devices in which the evidence in this case tends to place them, advance humane principles, and save the payment of damages to the injured.
The instructions of the court below to the jury seem to us very fair and impartial and sufficiently present the defendant’s side of this case to the jury. Other errors are assigned, but it is unnecessary to notice them in detail. We are convinced that substantial justice has been done and no error prejudicial to the appellant has been found.
By the Court. — Judgment affirmed.