Where there is a contract for the sale of specific goods in a deliverable state, but the seller is bound to weigh measure test or do some other act or thing with reference to the goods for the purpose of ascertaining the price, the property [ownership] does not pass until such act or thing be done and the buyer has notice thereof.
An example of this situation would be if Albert agreed to buy all the 600 mm wide pine timber in a supplier's warehouse at a price of $2.00 per meter, the quantity of such timber being unknown at the time of the sale.
In these circumstances, ownership of the timber would pass to Albert when all the 600 mm wide pine timber in the warehouse had been measured so that the quantity is known and the price can be calculated.