These were supplied in 1839 and four more were supplied to the GPK&R in 1840:  Mercury (No 1), Mazeppa (No 2), Wallace and Queen. In 1849, they supplied one of 2-2-2 formation for use on the Caledonian and Dumbartonshire Junction Railway, which later became part of the Edinburgh and Glasgow Railway.
This text details the supply of locomotives by a certain entity (GPK&R) to another entity (the railway company). The context is historical and focuses on the delivery of these locomotives over time.