Reed, J.
1. EVIDENCE wriMiig°-Vciuty Síteípret*0 writmg. I. On the trial plaintiff introduced parol evidence which tended to prove that defendant delivered the piano which it first delivered to plaintiff, and _ r J - received the old instrument from her, on ithe understanding- that she should test the instrument which she received, and that, if she was satisfied with it after giving it a fair trial, she should keep it at the price agreed upon, which w^as $375, and that defend7 ant should retain the oldpiano at $125, and credit that amount on the price of the new one; and that plaintiff should pay the balance of the price in monthly installments; but that, if she *134was not satisfied with it after such trial, she had the right to terminate the transaction and demand the return of the old instrument and the removal of the one delivered by defend'ant. Defendant introduced the following instrument in writing, which was signed by plaintiff and delivered to defendant at the time the contract was entered into:
“$375 June 2, 1883.
“For value received, I, the undersigned, * * * promise to pay to the order of W. W. Kimball Company three hundred and seventy-five dollars, at its office in Chicago, Illinois, as follows: One hundred and twenty-five dollars in hand paid by one second-hand piano; fifteen dollars on the second day of July; and fifteen dollars on the second day of each following month until the whole amount is paid, with interest on each payment at the rate of 10 per cent per annum from the date hereof until paid, with exchange, and a reasonable attorney’s fee if this note is placed in the hands of an attorney for collection. To secure the payment of the sums of money in the foregoing note contracted to be paid, together with interest, exchange and attorney’s fees, as therein provided, the undersigned hereby mortgages to said W. W. Kimball Company one piano, made by Emerson, No 28445, style ‘3,’ being the property sold by W. W. Kimball Company to me, in part payment for which the foregoing note is given. ' * * * ”
After introducing this instrument, defendant moved the court to exclude said parol evidence on the ground that it tended to prove a different contract from the one evidenced by the written instrument, and was therefore incompetent. The court overruled this motion, and by his instructions he left it to the jury to determine what the agreement between the parties was, and directed them that, in determining that question, they should consider the written contract and all that was said and done by the parties in the dealings and transactions which are the subject of the action. In our opinion, these rulings are erroneous.
*135By the written, contract, plaintiff bound herself unconditionally to pay $375 for the piano which defendant had sold to her. It also contains an express agreement between the parties that the second-hand instrument should be taken by defendant as payment of $125 of that amount. It evidences an unconditional sale of the new instrument to plaintiff and of the old one by her to defendant. The parol evidence tended to prove' a different contract. Under the familiar elementary rule that parol evidence is inadmissible to contradict or vary the terms of a written instrument, it should have been excluded, and the court, instead of submitting it to the jury to determine what the agreement was, should have determined the question by properly interpreting the instrument. 1 Greenl. Ev., § § 275, 277; American Emigrant Co. v. Clark, 47 Iowa, 671" court="Iowa" date_filed="1878-03-21" href="https://app.midpage.ai/document/american-emigrant-co-v-clark-7097739?utm_source=webapp" opinion_id="7097739">47 Iowa, 671.
2vaiue: \v?t-shown to be competent. II. A witness who was not shown to have any knowledge of the market value of such property was permitted, against defendant’s objection, to testify that the piano which defendant received from plaintiff was in her judgment worth $125. This evidence was J ” . incompetent. .Defendant’s liability, if it was liable at all, was for the fair market value of the piano. The opinions of witnesses who were shown to be acquainted with the value of such property in the market would be competent. evidence to prove such value. There can be no presumption, however, in the absence of a showing, that a witness is competent to form a correct opinion on the subject; and, until some showing of competency is made, the opinion of the witness is not admissible.
Eor the errors here pointed out, the judgment of the circuit court will be
Ee VERSED.