The systematic study of birds and other wildlife lagged behind the study of plants, but it began to catch up in the eighteenth century, driven by the scientific project to organize and classify the natural world, coupled with a growing appreciation for the variety and exoticism of life in other parts of the globe. With Britain's rise to pre-eminence as an international economic and colonial power, London became the center for collecting, studying and publishing on the birds of the world, particularly in the nineteenth century. Ornithological illustration until the 1830s was predominately by means of engraved prints that were then hand-colored. Beginning with Edward Lear and John Gould, illustrators turned to the use of lithography, a faster, less expensive, and more appropriate medium for showing texture and shading.