These griffin tripods are the earliest identified objects documenting the collaboration of the Bullock brothers. William’s innovative use of cast iron for fashionable, high-style furniture appears to be the earliest recorded example.

It is likely that William used George’s classical furniture to decorate the new Roman Gallery at his Egyptian Hall in Piccadilly, London, a museum which William commissioned to house his collection of curiosities brought back from the South Seas by Captain Cook (housed today in the British Museum). The masks, with their exaggerated ears embellishing each side of the triangular tops, may reflect William's interest in pre-Columbian artifacts or Greek masks.