A beautifully painted picture

I would like to take this opportunity to personally thank Ms. Joseph, along with my parents. Thanks to them, I have a clue as to the numerous allusions in this chapter (ch. 5) are referencing. When Hemingway refers to the Sorbonne, he is talking about the big university in Paris. The "Quarter" is actually the Latin Quarter and is where most students hang out and enjoy cheaper foods and drinks. Throughout this chapter, Jake and his coworkers are seen galavanting throughout the streets of Paris. Hemingway did a phenomenal job of painting a picture in the reader's mind through his elicit details. Even though I have had the privilege of traveling to Paris, I believe I would still have a decently vivid picture as to the experiences the characters are encountering. One thing I do have to ask is what is a chap? I am going to look it up real quick but I figured I would pose the question on here so anyone could input.