the contractor shall send to the employer once in every month an account giving particulars， as full and detailed as possible， of all claims for any additional payment to which the con - tractor may consider himself entitled and of all extra or addition - al work ordered by the employer which he has executed during the preceding month.
no final or interim claim for payment for any such work or expense will be considered which has not been included in such particulars. provided always that the employer shall be entitled to authorize payment to be made for any such work or expense， notwithstanding the contractor''s failure to comply with this con - dition， if the contractor has， at the earliest practicable opportuni - ty， notified the employer in writing that he intends to make a claim for such work.30 plant， temporary work and materials
all constructional plant， temporary works and materials provided by the contractor shall， when brought on to the site， be deemed to be exclusively intended for the execution of the works and the contractor shall not remove the same or any part there - of， except for the purpose of moving it from one part of the site to another， without the consent， in writing， of. the employer.
upon completion of the works the contractor shall remove from the site all the said constructional plant and temporary works remaining thereon and any unused materials provided by the contractor.
the employer shall not at any time be liable for the loss of or damage to any of the said constructional plant.temporary works or materials save as mentioned in clauses 8 and 35 here- of.
in respect of any constructional plant which the contractor shall have imported for the purpose of the works， the employer will assist the contractor， where required， in procuring any.nec - essary government consent to the re - export of such construc- tional plant by the contractor upon the removal thereof as afore - said.
the employer will assist the contractor， where required， in obtaining clearance through the customs of constructional plant， materials and other things required for the work.31 measurement of quantities
the quantities set out in the bill of quantities are the estimated quantities of the work， but they are not to be taken as the actual and correct quantities of the works to be executed by the contractor in fulfillment of his obligations under the contract.
the employer shall， except as otherwise stated， ascertain and determine by measurement the value in terms of the contract of work done in accordance with the contract. he shall， when he requires any part or parts of the works to be measured， give no - tice to the contractor''s authorized agent or representative， who shall forthwith attend or send a qualified agent to assist the em - ployer in making such measurement， and shall furnish all particu - lars required by either of them. should the contractor not at - tend， or neglect or omit to send such agent， then the measure - ment made by the employer shall be taken to be the correct mea- surement of the work.