[2] The firm was initially involved in exporting cotton and coffee, and in importing manufactured goods from Britain[3] McInroy had set up a store in Demerara in 1790 and was using ships to trade between there and Grenada.
Although the partnership owned at least two cotton plantations in Demerara, it was the success of the store that became the most significant aspect of the new enterprise and it resulted in Parker and Robertson returning to Britain to develop business contacts.
The two men set sail in haste for Grenada in 1795 when they heard news that the combination of a French landing on the island and an uprising by Afro-Grenadians there was threatening British rule.
McInroy managed to escape the island with around £9000 in goods by using the partnership's sloop, called Rambler, which then evaded a close-fought boarding attempt by a French privateer.
[1][7] In 1813,[8] the prosperous and well-connected Philip Frederick Tinne, a Dutchman of Huguenot descent who already had experience of working coffee plantations in Demerara, joined the firm in Liverpool as a full partner.
[8] The enterprise grew to become owners of both ships and plantations and also exporters of coffee, molasses, rum and sugar from the West Indies to the British ports of Liverpool and Glasgow.
[14] The latter became a feature of society in British Guiana following emancipation of slaves because plantation owners needed a new source of labour and they found it in the importation of people from India.
[8] The distinctive crest used by the firms may owe its origin to the incident with the Rambler which, sailing without a flag and being threatened with boarding, improvised a solution by sewing together a white shirt between the legs of a pair of blue trousers.
[1] Sandbach and Tinne lived next-door to each other for some time, at 27 and 29 St Anne Street, Liverpool, from where they had a good view of shipping on the River Mersey.