[4] Among Gem's sporting interests was the game of rackets, which he played at the Bath Street Racquets Club adjacent to the Racquet Court Inn in Bath Street, Birmingham with his friend Augurio Perera, a Spanish merchant based in Birmingham.

Frustrated at the complex and expensive facilities required for rackets, however, the two developed a similar game that could be played outdoors and may have been played on Perera's croquet lawn at 8 Ampton Road in Edgbaston, incorporating elements of rackets alongside features of the Basque game of pelota.

[5] It thus clearly pre-dates the game of sphairistikè, whose rules were published and for which equipment was sold by Major Walter Clopton Wingfield from March 1874.

Gem and Perera's game also bore a closer resemblance to modern tennis than Wingfield's in several significant respects, most notably in being played on a similarly sized and configured rectangular grass court, rather than the hourglass-shaped court with a 'waist' at the net that featured in Wingfield's sphairistikè.

[3] Gem died on 4 November 1881 as the result of an accident which occurred on 25 June that year, at the military camp in Sutton Park.