Under the balustrade of the Braithwaite Hall is the usual line of portrait busts of the great and good, so familiar a feature of Victorian libraries. Most are the uncontroversially admirable like Shakespeare and Newton, though Croydon might have been slightly edgy in including Darwin, whose monkey theory was still dynamite in 1892, and Locke, the Enlightenment philosopher whose theories of the social contract so influenced the American revolutionaries.On the other hand, it is inexplicable why John Tillotson, a now-forgotten 17th century divine, should be absolutely in the centre. Perhaps he did great things for Croydon when he was Archbishop of Canterbury in the 1690s, but otherwise he seems to be notable solely for being a reasonable sort of bloke who steered the C of E through the turbulent waters of the Glorious Revolution.
In the absence of any evidence to the contrary, I assume they are the work of Edwin Roscoe Mullins, who carved the allegorical groups below, though they may have been a bit off-the-shelf for him. Perhaps they were supplied by the Aumonier Studio who did the heraldic work in the porch.