David Ricardo 
On The Principles of Political Economy, and Taxation. Illustrated 

The book concludes that land rent grows as population increases. It also presents the theory of comparative advantage, the theory that free trade between two or more countries can be mutually beneficial, even when one country has an absolute advantage over the other countries in all areas of production.
Ricardo famously analysed the impact of the adoption of machinery on the different classes of society, revising his earlier view that mechanization could be expected to be of benefit to each of the classes of the society. 

About the author

David Ricardo (18 April 1772 – 11 September 1823) was a British political economist, one of the most influential of the classical economists along with Thomas Malthus, Adam Smith and James Mill. He was also a politician, and a member of the Parliament of Great Britain and Ireland.