delivered the opinion of the court.
*2992. Appeal and error, § 1471 * —when admission of parol evidence not ground for reversal. In an action on a written contract where both parties offer parol evidence as to the meaning given by the trade to a certain phrase, neither party can avail of any objection to such evidence on appeal.
3. Contracts, § 198 * —what interpretation to be given to trade term. In an action on a contract for installing a heating and ventilating plant, a provision calling for the payment of a certain part of the contract price “when steam is turned on plant” is to be construed in accordance with the significance given to the term by the trade.
4. Contracts, § 198 * —how trade term construed. The provision in á contract for installing a heating and ventilating plant that the second instalment of the purchase price shall be paid “when steam is turned on plant” is to be construed as meaning when steam is generated in the boiler, circulates through the steam mains and branches leading to the radiators, and the plant is in operation.
5. Contracts, § 246 * —when certificate not essential to payment of part of contract price. If the contract makes no provision that a certificate of the superintendent, that the instalment of the contract price is due, shall be procured before the payment of the instalment, such a certificate is not prerequisite to a right to demand the payment of such instalment where the terms of the contract have been complied with and the work performed.
6. Mechanics’ liens, § 61 * —when Act not applicable to subcontractor. Section 5 of the Mechanic’s Lien Act (J. & A. ¶ 7143) does not apply to subcontractors.
7. Mechanics’ liens, §66 * —when verified statement by subcontractor not necessary. A request for a verified statement from a subcontractor under section 22 of the Mechanic’s Lien Act (J. & A. If 7160) comes too late when made after the subcontractor has abandoned the contract for the other party’s breach, and letters thereafter written making such request are inadmissible.