According to his own description, the illustrations in his books are sketches from his time in Guangzhou. He claims that the information about Chinese gardens is partly from what he saw for himself there, and partly based on what he was taught by Chinese artists.
根據他自己的描述，著作中的圖樣，都是他在廣州的現場速寫；有關中國園林的資訊，則有大部份「是向中國藝術家請教的」。