<p>Artist Norman Thelwell is best known for his cartoons depicting plump, petulant ponies and their young riders, but The Effluent Society shows another aspect of his work and character. Thelwell was passionate about the countryside and nature. During his life he became increasingly concerned about the impact of development, pollution and society's treatment of the environment. When The Effluent Society was first published in 1971, his concerns w...