 In 1861 he was invited to London to assist Francis Fowke on the buildings connected with the horticultural gardens then in course of formation.Some of the arcades were entrusted to him, and to his successful treatment of them with terracotta the subsequent popularity of that material was largely due.The new buildings for the South Kensington Museum gave further scope for the exercise of Sykes's powers, and upon the decoration of these he was engaged until his death.