Ralph Abercromby (1842-1897) was a famous British meteorologists in the 19th century. He proposed the principles of weather charts and used them in weather forecasting. He opened up the beginning of weather forecast by weather charts analysis. Based on the brief introduction of Abercromby’s life, this paper focuses on his monograph: Principles of Weather Forecasting by Means of Weather Charts. After outlining the work frame and basic concepts, the paper presents Abercromby's understanding of meteorology, including seven types of isobars, classification of the weather type, and how to carry out the weather forecast. Finally, Abercromby's contribution and influence on Meteorology are combed and summarized.