341. Price fixed by the contract.

There are two ways in which the price may be fixed by the contract. First, the contractor may have undertaken to execute specified work for a specified sum, in which case a claim by him for the lump sum price or an agreed instalment is a liquidated demand and he can apply for summary judgment1. Secondly, where the extent of the work is at the time of the contract uncertain, the contract may provide that the price be ascertained by measuring the work done against items in a bill of quantities or in a schedule of rates