The question in this case in whether or not the plaintiff fully performed his contract of March 26, 1886. The contract stipulated for payment of one-half of the price before, and of the other half when, the machinery was completed and successfully running. Now, in addition to the full payment of the one-half, substantially three-fifths of the other was paid in three successive payments; the first within one and the last not until six weeks after the commencement of actual operations. There is significance in these latter payments. While not conclusive on the company, the indicate that in its judgment, for a while at least, the plant fully satisfied all the conditions of the contract, and are properly to be considered in determining the merits of the defense made to this action. That defense is that the plant was improperly and unskillfully constructed, of weak and defective parts, of material not adapted to the work which it was designed to perform, and that its actual working capacity did not exceed 350 tons a day. The answer, besides its defensive allegations, contained a counter-claim.

The first matter we notice is the alleged error in the testimony of Charles S. Brown, who, from certain account-books which he presented, was permitted to testify as to the actual working of the plant between October 18th and November 7th, giving in that testimony the actual hours the plant was working, the number of tons crushed, the hours of delay, and the causes therefor. This witness was sent by Mr. Blake to superintend the erection of the plant, to watch its workings when completed, and to make any needed repairs, improvements, or changes. At his suggestion, after the plant commenced work, the defendant's superintendent directed the foremen of the mill to keep these books. The foremen, of whom there were four, generally made the entries on the books, though sometimes Brown did the writing at their dictation. The entries were made daily; at least, that was the intention and the general practice. The amount of ore crushed, as disclosed by these books, corresponded within a few tons with the amount testified to by the officers of the defendant company. Brown himself was present at the mill most of the time during the day, and had a general knowledge of the accuracy of these entries, so far as respects the work during that time. We think the testimony was competent. The books were kept by the direction of the defendant's superintendent, and the entries made by its foremen. They were intended to be, and in fact generally were, contemporaneous with the matters stated; and their substantial accuracy is corroborated by the personal knowledge of the witness, and the near coincidence of the general result with that vouched for by the defendant. They may not have been account-books of the defendant, in the technical sense of the term, such as are generally admissible against a party, but they were memoranda made under the direction of the defendant, for the purpose of preserving a record of certain facts, and made under such circumstances as to be worthy of a measure of credence as against it.

A second matter is this: The general manager of the defendant was asked what, in his judgment, was the daily capacity of the mill. This question was objected to, on the ground that the witness was not shown to be competent to testify as an expert, which objection was sustained. How much knowledge a witness must possess before a party is entitled to his opinion as an expert is a matter which, in the nature of things, must be left largely to the discretion of the trial court, and its ruling thereon will not be disturbed unless clearly erroneous. Manufacturing Co. v. Phelps, 130 U. S. 520, 9 Sup. Ct. Rep. 601; Railway Co. v. Warren, 137 U. S. 348, 11 Sup. Ct. Rep. 96, Coasting Co. v. Tolson, 139 U. S. 551, 11 Sup. Ct. Rep. 653. This witness testified that he had been general manager of the defendant company for six years, and that he was at the mills as often as twice a month, and usually went there once a week. He does not appear to have been a practical machinist, or to have had any special knowledge of mining or crushing machinery. He was not superintendent of the workings of the mine or of the machinery, and does not claim to have been there regularly, or, indeed, oftener than once a week, and, as general manager, was apparently more employed in the financial and outside business affairs of the company than in the details of the mining or the practical workings of the machinery. We think the ruling of the trial court in excluding his opinion was right; at any rate, it cannot be adjudged clearly erroneous.

Another matter is also complained of, and to a clear understanding of this question the course of the trial must be stated. The plaintiff opened by proving the construction of the mill, and, in a general way, that it had the capacity of 600 tons daily, and also the payments by the defendant. He then rested, and the defendant introduced testimony to show that the mill was not of the stipulated capacity, and explaining the circumstances of the subsequent payments. This included evidence of the actual workings of the mill from the 1st of October, 1886, to the 1st of January, 1888, the difficulties that were encountered in its workings, the stoppages, what was done on such occasions, and the efforts to remedy supposed defects, as also the opinions of competent witnesses as to its capacity; in other words, it went fully into the matter of the actual workings of the mill, and its alleged incapacity to do the stipulated amount of crushing. In rebuttal, plaintiff called the witness Brown, who gave the testimony heretofore referred to from the memorandum books. It appeared from his testimony that the books had been kept from October 18th till he left, in March following. He had made out from them a statement of facts respecting the workings of the mill from October 18th to the 7th of November, which he had forwarded to the plaintiff, and the details of that statement, as verified by the books, were the sum and substance of his testimony. After he had finished, and the plaintiff had rested in his rebuttal, the defendant called a witness named Hall, who testified that he had examined the books, and he was then asked what the average run per hour was for the months of November, December, and January, separately, as shown by those books. This testimony was objected to and ruled out, and of this defendant now complains. We think the ruling of the court was right. If the defendant had a right, after the plaintiff had closed his case in rebuttal, to introduce any testimony at all, such right was limited to the new matters brought out in the rebuttal; and while the fact of the existence of these books, and that they were kept for several months, was then disclosed for the first time, the only matters therefrom presented to the consideration of the jury were those transpiring between October 18th and November 7th. As to those matters, the witness Hall was given full liberty of testifying, and that certainly was as far as the defendant's rights extended. These books were its own books at least, made by its own employes under the direction of its superintendent. It did not offer them when it was making its defense, and the fact that certain portions of them are brought to the attention of the jury on plaintiff's rebuttal did not entitle it thereafter, and after the plaintiff had finally closed his testimony, to present the whole matter of these books in evidence.

Still another matter is this: Defendant called as a witness Smith M. Weed, who testified that he was a lawyer, but not in actual practice, and had not been for 8 or 10 years; that he was one of the defendant's directors; that he was interested in mining iron ore; and that that had been his principal business and taken most of his time for the past 20 years. He was then asked this question: 'What is understood by a day in the iron mining business?'—the defendant's counsel saying that he offered to prove the independent fact that a day means two shifts of 10 hours each in iron mining. This testimony was offered for the purpose of interpreting the stipulation in the contract guarantying a capacity of 600 tons daily; in other words, the defendant sought to prove by this that the contract was for a mill capable of crushing 600 tons in 20 hours, instead of 24 hours. This testimony was objected to, and the ruling of the court was stated in these words: 'I do not think that it is admissible, unless you propose to show that that local custom was known to both contracting parties.' Evidently the court understood that a local and not a general custom was sought to be proved. It is true the question is general in its terms; but for some reason not altogether apparent-perhaps from the course of the testimony of this witness the court understood the question to be directed to a merely local usage, to-wit, that obtaining in the mine of which the witness had been speaking. If it was such local usage, the court was right in holding that it could not affect the meaning of the terms used in the contract unless known to both parties; if a custom prevailing generally, there may be a presumption of knowledge, and the testimony might have been competent without anything directly bringing home knowledge of it to the plaintiff. If the court misundertood the scope of the question, counsel should have corrected the misunderstanding at the time; but, simply noting an exception, they passed on to a further and different examination. They were notified that the court was ruling on an offer to prove a local custom. If that was not what they sought to prove, they should then have stated the fact. Saying nothing, it must be held that the court properly interpreted the scope of the offer, and it will not do now to say that the language of the question is broad and comprehensive, and that the court ruled out evidnece of a general custom and understanding in the mining business as to the meaning of a common word. When the general manager of the company was thereafter on the stand, a substantially similar question was put to him by counsel, and an objection was sustained without any comments by the court. Of course, if that ruling stood by itself, its correctness might have to be determined by all implied in the question; but, in view of that which had previously passed, we think it fair to hold that the court was simply continuing the ruling which it previously made, and not that it was passing upon a new and independant question.

We have been not a little embarrassed by this matter, and the question is not free from difficulty; but we think the interpretation we have given is the correct one; at all events, if not the only, it is a fair, interpretation of the proceedings, and error is not to be presumed. The rulings of the trial judge are to be taken as stated by him, and not to be carried beyond his own statement, unless clearly remanded by the circumstances of the case. It is worthy of note in this connection that, according to the testimony, defendant's mill during certain months worked 22 hours a day. And further, that in a letter written by the general manager of the company to plaintiff in 1881, preliminary to the contract under which the first crusher was furnished by plaintiff, the writer says: 'What we want is appliances that will crush (without roasting) 200 tons of crude chunk ore in 24 hours, and stand the racket month in and month out without break-downs and stoppages. * * * Now, if we can do the work we speak of, (200 tons daily,) and dispense with rolls, it is a great desideratum.' Evidently 'daily at that time was used in the ordinary significance of the term, and it would require very satisfactory testimony to show that in this later contract it was used in a different sense. We think it must be held that the court did not err in its rulings in this respect.

The final matter is concerning the instructions. To the general charge no exceptions were taken. Eighteen special instructions were asked, and in respect to them the bill of exceptions states: 'The court did not charge either of said requests, except as he had charged. For the refusal of the court to charge in the specific language of said hereinbefore-recited requests, the defendant's counsel then and there duly excepted.' In this way only is any exception taken to the matter of the instructions. But this wholesale exception is not sufficient. Connecticut Mut. Life Ins. Co. v. Union Trust Co., 112 U. S. 250, 5 Sup. Ct. Rep. 119; Burton v. Ferry Co., 114 U. S. 474, 5 Sup. Ct. Rep. 960.

These are the only matters presented for our consideration.

The judgment will be affirmed.