Upon the trial the plaintiffs offered evidence and claimed to have proved that they bored four wells of the aggregate depth of 115 feet; that in boring these wells they started three or four other holes that were abandoned on account of striking solid bottom; and that there were about sixteen feet drilled in the holes that were so *307abandoned. The plaintiffs claimed to recover the contract price, |2.00 per foot for this drilling.
The defendant objected, on the ground that the written proposals made by the plaintiffs to the defendant did not include any such drilling And it appeared, in fact, that the proposals did not include any such holes. The plaintiffs offered to prove by their own agents that it was a custom of the trade of driving wells to charge for driving wells which did not produce water and which were abandoned. The defendant objected to this evidence upon the ground above stated, and also on the gi’ound that the complaint contained no allegation making such evidence material. The court overruled this objection and admitted the evidence.
In reference to this evidence the court charged the jury as follows: “ The plaintiffs include as a part of the work of digging these wells a number of feet driven in wells which proved to be failures. This charge they make upon the ground that it is a custom of the trade or business of digging wells like those contracted for, to charge for digging these wells which have to be abandoned as parts of the wells which are completed. Some evidence was offered from which it is claimed that you will find that such a custom exists. If you find there is a known and established custom in the trade to so charge, the parties will be presumed to have contracted with the custom in view and you can allow the claim. But it must be a universal, certain and general usage and custom of the trade, so proved by the evidence, and not a custom of the plaintiffs only, or the plaintiffs can recover only for the number of feet actually driven by them in the wells which were completed.”
This instruction seems to us to have been insufficient for the guidance of the jury in that it does not state what must be proved in order to show that a custom is a known and established one; and also in treating the presumption which might be drawn from such a custom as one of law. There was no evidence that the defendant had any actual knowledge of the custom, and she was liable if at all by reason of the custom, because it was a general, known and established one. *308At the common law a custom was not an established one unless it was shown to have existed from time immemorial. By the more recent law the true test of such a custom is its having existed a sufficient length of time to have become generally known and to warrant the jury in finding that the contracts were made in reference to it. Powell v. Bradlee & Co., 9 Gill & Johnson (Md.), 220; Burroughs v. Langley, 10 Md., 248; Smith v. Wright, 1 Caines (N. Y.), 45; Treadwell v. Union Ins. Co., 6 Cowen (N. Y.), 273; Crosby v. Fitch, 12 Conn., 410 ; Bliven v. New England Screw Co., 23 Howard, 431. No person can be made liable by reason of a custom, except when it is shown that he had knowledge of the custom. In eases where the custom is a limited or special one actual knowledge must be proved. And every custom is a limited or special one until it is shown to have existed long enough to sustain the test above stated.
The defendant called as a witness her son who was also her business agent. He testified generally in her behalf and also in support of her counterclaim. Upon cross-examination counsel for the plaintiffs showed him the letter, Exhibit D, and asked him if he received the original of that letter. He replied that he might have received such a letter. Counsel then offered the letter in evidence, and on being asked for what purpose it was offered, stated: “For the purpose of refreshing the recollection of the witness whether Smith & Winchester offered to proceed to put down as many wells, in addition to the four wells, as he desired.” No other ground for the admission of the letter was stated by the counsel. After some considerable discussion between the opposing counsel, and with the court, the court admitted the letter to be laid in to the jury and read in evidence, remarking in doing so that “ it seemed to him to be proper in reply to the defendant’s case.” Counsel for the defendant objected, but not on the ground that the original was not produced, nor that it was offered at an improper time.
We think the admission of this letter, without carefully instructing the jury as to the part which might be read and the purpose for which it was admissible, was manifestly erro*309neous. It was a letter written by the plaintiffs only a short time before the suit was commenced, and, as appears on its face, after the dispute which resulted in the suit had already begun, setting forth with care and with considerable detail their own case both in chief and in reply to the counterclaim of the defendant. If it had been used only for the purpose of refreshing the recollection of the witness no harm could have been done, for it would not have been read to the jury. As evidence in reply to the counterclaim some three or four-lines near its close would perhaps be admissible. For this purpose the only fact which could legitimately be proved by the letter was, not that the plaintiffs were willing to fulfill their guarantee, but that the witness had knowledge of their willingness so to do, and the few lines might possibly be claimed to convey such knowledge. But this part of the letter would not be admissible, except in connection with evidence showing that the original letter was received by the witness before the expenses were made which were the subject of the counterclaim, and no such evidence appears to have been given. The letter was admitted generally, and the whole of it went to the jury as proper evidence for them to consider. Letters written by a party are not evidence for him any more than his declarations. This letter was not evidence of any fact stated in it. It was a naked claim by the plaintiffs that they had kept their agreement. It should not have been admitted.
The other assignments of error we do not find it necessary to consider. Most of them are not well taken, and so far as they are well taken the grounds will not be likely to occur upon another trial.
There is error and a new trial is granted.
In this opinion the other judges concurred.