All matenal used in this contract is u r nt to specified, and the <br />entire job is to done in a asst and workmanlike manner. Any deviation or <br />alteration from the specification herein agreed upon involving extra cost of <br />labor and/or matedals vAll be t oil upon tt n order or Instructions, <br />and Ml become an extra charge over costs as mentioned In this contract,. <br />