This is part 2 of the chapter, about curved lines. Because I've been so busy with Gouache Week, I've barely looked into the chapter, I'll just present some of the main points and images. I'll pass on my own responses and leave the discussion to you in the comments.
1. Curved lines have not the moral integrity of straight lines....without the steadying power of straight lines and flatnesses, curves get out of hand and lose their power....We recognise this integrity of straight lines when we say anybody is "an upright man" or is "quite straight," wishing to convey the impression of moral worth.
2. Always be on the look out for straightnesses in curved forms and for planes in your modelling.
3. Illustration showing the "Power of Curved Lines to Convey Energy."
4. Illustrating the flow of lines (in Botticelli's Venus) on which the Rhythmic Unity of the Picture Depends.
5. Rhythmic Lines in Veronese Rape of Europa.
6. Diagram of "Clash of Lines" from Uccello's Battle of St. Egidio
7. Showing how Lines unrelated can be brought into harmony by the introduction of others in sympathy with them (also below)
8. Indicating the sympathetic flow of lines that give unity to this composition.
The Practice and Science of Drawing is available in various formats:
1. Inexpensive softcover edition from Dover, (by far the majority of you are reading it in this format)
3. Free online Archive.org edition.
Articles on Harold Speed in the Studio Magazine The Studio, Volume 15, "The Work of Harold Speed" by A. L. Baldry. (XV. No. 69. — December, 1898.) page 151.
and The Windsor Magazine, Volume 25, "The Art of Mr. Harold Speed" by Austin Chester, page 335. (thanks, अर्जुन)
GJ Book Club on Pinterest (Thanks, Carolyn Kasper)
New GJ Facebook page, credit Jenna Berry
Overview of the blog series
Announcing the GJ Book Club
Chapter 1: Preface and Introduction
Chapter 2: Drawing
Chapter 3: Vision
Chapter 4: Line Drawing
Chapter 5: Mass Drawing
Chapter 6: Academic and Conventional
Chapter 7: The Study of Drawing
Chapter 8: Line Drawing, Practical
Chapter 9: Mass Drawing
Chapter 10: Rhythm
Chapter 11: Variety of Lines
Chapter 12: Curved Lines
Chapter 13: Variety of Mass
Chapter 14: Unity of Mass
Chapter 15: Balance
Chapter 16: Proportion
Chapter 17: Portrait Drawing
Chapter 18: Visual Memory
Chapter 19: Procedure
Chapter 20: Materials