Complex sentence: The first building to be erected that still forms part of the museum was the Sheepshanks Gallery in 1857 on the eastern side of the garden; its architect was civil engineer Captain Francis Fowke, Royal Engineers, who was appointed by Cole.
Split into simpler sentences: The first building to be erected that still forms part of the museum was the Sheepshanks Gallery in 1857 on the eastern side of the garden. Its architect was civil engineer Captain Francis Fowke, Royal Engineers, who was appointed by Cole.