LENNON WYLIE'S WEB SITE listing people/places on old Belfast streets, listed John Calwell in 1861 at 2 Curtis St. "sewed muslin warehouse"  I know Belfast of that era was a huge center for weaving textiles.  I am guessing there is a connection?  Also the bride's father Hugh Thompson was a weaver originally from Dorchester, Eng. , but I do not find further reference to him. Both families were Presbytrian and George & Eliz later had their Children baptised 1824/25 at Rosemary St. Church. 
George worked for the Moses Sta(u)nton  a "room paper, carpet & damask Warehouse/later manufacturer at 9 Donegal St.