This commonplace book consists of brief writings and observations on agriculture, arts and manufactures, commerce, the army and navy, canals and roads, weights and measures, general politics, finance, and population. It includes a sketch of the Battle of Quebec groundworks and layout.

The first fifteen volumes of these "Notes of Travel" are Lea's account of his trips to Europe during 1832 and 1852-1853. He met with naturalists, scientists, and did much sightseeing in England, France, Germany, Italy, and Austria. He records in detail visits and discussions with scientists, and makes sketches of many of the places he saw, particularly the Rhine River. The sixteenth volume is a memorandum book, 1853, containing accounts and expenses while in Europe.