How Round Is Your Circle?: Where Engineering and Mathematics Meet (Hardcover)

~ (Author), Chris Sangwin (Author) "There are many convincing ways to justify a result..." (more)
Key Phrases: hatchet planimeter, linear planimeter, departure from roundness, Scott Russell, British Standard, United Kingdom (more...)

Editorial Reviews

Review

There are many books that include ideas or instructions for making mathematical models. What is special about this one is the emphasis on the relation of model- or tool-building with the physical world. The authors have devoted themselves to making wood or metal models of most of the constructions presented; 33 color plates nicely show off their success in this area.
(Stan Wagon American Scientist )

The question posed by this book turns out to be a real toughie, but nevertheless the authors urge you to answer it. This gem of a book tackles several such questions, revealing why they are crucial to engineering and to our understanding of our everyday world. With a nice emphasis on practical experiments, the authors do a refreshing job of bringing out the mathematics you learned in school but sadly never knew why. And they show just how intuitive it can be.
(Matthew Killeya New Scientist )

This book has many gems and rainbows. . . . The book will appeal to all recreational mathematicians . . . not just because of the way it is written, but also because of the way puzzles, plane dissections and packing and the odd paper folding or origami task are used to bring a point home. . . . More than one copy of this book should be in every school library. . . . It should help to inspire a new generation into mathematics or engineering as well as be accessible to the general reader to show how much mathematics has made the modern world.
(John Sharp LMS Newsletter )

This is a great book for engineers and mathematicians, as well as the interested lay person. Although some of the theoretical mathematics may not be familiar, you can skip it without losing the point. For school teachers and lecturers seeking to inspire, this is a fantastic resource.
(Owen Smith Plus Magazine )

This book is very clearly written and beautifully illustrated, with line drawings and a collection of photographs of practical models. I can strongly recommend it to anyone with a bit of math knowledge and an interest in engineering problems--a terrific book.
(Norman Billingham Journal of the Society of Model and Experimental Engineers )

Part magic show, part history lesson, and all about geometry, How Round Is Your Circle? is an eloquent testimonial to the authors' passion for numbers. Perhaps it will spark a similar interest in some young numerophile-to-be.
(Civil Engineering )

This book can be dense, but it is great for dipping into, a rich resource of interesting thinking and project ideas. Bryant and Sangwin, the engineer and the mathematician, must have had a great time putting this book together. Their enthusiasm and humor shine through.
(Tim Erickson Mathematics Teacher )

Review

This book is a mine of exploration and information. I would recommend it to anyone with an interest in how things work and in how mathematics can help make sense of the world. Budding engineers and mathematicians will find it an inspiration.
(John Mason, The Open University )

See all Editorial Reviews

Product Details

• Hardcover: 352 pages
• Publisher: Princeton University Press (January 3, 2008)
• Language: English
• ISBN-10: 069113118X
• ISBN-13: 978-0691131184
• Product Dimensions: 9.3 x 6.4 x 1 inches
• Shipping Weight: 1.4 pounds (View shipping rates and policies)
• Average Customer Review: 4.8 out of 5 stars  See all reviews (5 customer reviews)
• Amazon.com Sales Rank: #60,548 in Books (See Bestsellers in Books)

  Popular in these categories: (What's this?)

  #2 in	Books > Professional & Technical > Engineering > Special Topics > Measurement
  #4 in	Books > Science > Mathematics > Applied > Engineering
  #25 in	Books > Professional & Technical > Professional Science > Mathematics > Geometry & Topology > General Geometry

Customer Reviews

Most Helpful Customer Reviews

10 of 10 people found the following review helpful:

5.0 out of 5 stars Modeling to illustrate mathematics, June 22, 2008

By	Bruce R. Gilson (Wheaton, MD United States) - See all my reviews (REAL NAME)

This book is in the tradition of the famous book "Mathematical Models," by H. Martyn Cundy and A. P. Rollett. It shows how to create models that illustrate particular mathematical laws, and in fact Cundy was consulted, while he was still alive, by the author. It is a worthy successor to Cundy & Rollett's book, concentrating mainly in two areas: linkages to draw straight lines and curves, and constant-breadth shapes, though entering a few other areas.

An example of the type of problem this book considers is: How would you construct "the first" protractor or ruler, if there were none already existing?

The spirit of the book is the kind of practical thinking that is thought of as engineering, but the mathematics discussed is fundamental. This is a highly recommended book.

10 of 10 people found the following review helpful:

5.0 out of 5 stars Or how trisected is your Angle?, May 18, 2008

By	R. H. Pratt "Math Phile" (Henderson, NV) - See all my reviews (REAL NAME)

What this book shows you is that you can really understand Mathematics, when you try to build things, even something simple, like cutting a good circle from wood. Many areas of mathematics are discussed that people instinctively feel they understand, such as the roundness of a curve or circle, dividing an angle into 3 equal parts and other interesting Objects De Mathematica. You will find fascinating ways to really model the pythagorean theorem, or gather the sectors of a circle to make an equivalent triangle. There is much to discover between these pages, and Mathematics becomes concrete, objectified, and deeply understood. As another example: "what would a 3 dimensional object that has constant width throughout (based on the tetrahedron) Look like? You can see what this object looks like, when you read the work, and see the model. To add to your understanding, the Authors have constucted Models of the various mathematical principles and ideas, that you can see with your own eyes: such as "two-tip" polyhedrons, and summing the squares of numbers from 1 to n. Reading this book will improve your grasp of mathematics, as well as inspire you to study Engineering, if you havent already. Future Engineers, will be much smarter for having read this great book. Richard H. Pratt, Ph.D.

5 of 5 people found the following review helpful:

4.0 out of 5 stars Surprises, Ingenuity and ... a Few Disappointments, August 18, 2008

By	G. Poirier (Orleans, ON, Canada) - See all my reviews (TOP 500 REVIEWER)    (REAL NAME)

This fascinating book flags the spot where engineering and mathematics meet. Each chapter essentially covers a different subject: from linkages to vernier scales to slide rules to balancing dominoes to suspension bridges and so much more. The authors combine the rigidly theoretical approach of mathematics to the very real, practical and physical problems faced in engineering. The result is an amazing romp through various subject areas where the two meet. Very few mathematical derivations are presented here; instead, appropriate references are given throughout (but the reader may feel the urge to attempt some of the derivations him/herself). Some of the results are truly amazing, e.g., stacking a leaning tower of dominoes; some are very ingenious, e.g., the vernier scale and the slide rule; and some chapters I found rather disappointing, e.g., the chapter on suspension bridges - a subject dear to my heart that somehow I felt was lacking. The writing style can be a model of clarity for many chapters while, unfortunately, others seem rather cloudy by comparison; for example, I would place the first (Hard Lines) and seventh (Follow My Leader) chapters in the second category. But overall, the reader is bound to find this book very much worth the read. Those who are likely to relish this book the most would include mathematicians, engineers and serious science buffs. This book could also be used as a supplementary text for related university courses.