Customer Reviews

Geodesic Math and How to Use It

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Hugh Kenner's book is the bible of geodesy. While other books provide you with tables and some of the rudiments of the theory of geodesic domes, 'Geodesic Math and How to Use it' gives you a first-principle look at how domes are developed from a mathematical/geometrical point of view. Most importantly, Kenner introduces the reader to a novel metric for both describing the location of geodesic points in space and calculating their exact positions, so you can develop your own chord factors rather than relying on tables without understanding the underlying math.

Seemed over-technical at 1st, but after about a year has been my reference book on geodesics & making all kinds of geodesic domes... It lists chord factors (lengths of segments before applying radius of dome) on tables to 7 decimals for various domes @ the end of the book if you don't want do calculate w/formulas provided. If your familiar with trigonometry, it will let you jump around chapters that are of more interest.

This book was originally copyrighted in 1976, but not edited for this 2nd paperback 2003 Edition (glossy color cover). The author, Hugh Kenner (1923-2003), has compiled a very thorough book. Very well written & explained in orderly fashion with excellent general layout & (especially for the time) detailed diagrams plus cross page-references. IMO there is very little that I would change except for replacing current diagrams with modern CAD generated illustrations, that's about it.

Has 172 pages with several blank pages for notes (I note in the wide margins instead) & is 8.7 x 8.7 x 0.5 inches. Not a small book but not a big bulky one either. Makes for a lot of information handy to store just about anywhere...
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I found many formulas & shortcuts throughout the book. From Chapter 12 I plotted a 16 frequency (# of divisions making total # of triangles) icosahedron (the typical geodesic polyhedron shape) dome with 3880 chords or "struts". Even made them into arcs for a perfectly round sphere. Chapter 12 has "Using the Tables" with a simple symmetric triangle xyz-grid on a spreadsheet. Each chord calculated does not rely on another chord's result, so chance of error is greatly reduced. Chapter 14 "Truncations" has "Truncation by Rotation", which saves time on calculating the rest of the chords in dome, or moving chords by their symmetry.

This "still nicely" bound book after a lot of use covers tension & tensegrities, subdivisions, great circles, symmetry & breakdowns, choosing a polyhedron, spherical coordinate system, ellipses & superellipses, truncations, space frames & many kinds of angles - plus charts & other resources @ the end.

A free program on the web called Windome is useful to 8 decimals, but lacks input parameters like radius... So I use it to verify chord factors. From 2-16v involving about 12,240 chords plotting all verified (to 15 digits) on 1st try. Besides spreadsheets, formulas can be used in programming like "The R Project", formulas & programs are also written for old Hewlett-Packard HP-35, 21 & 45 series calculators & programs filed with the HP-65 library (circa mid-1970's). I guess it also goes to show Hewlett-Packard has a history in the PC & hardware programming business...

One thing - spherical coordinate symbols for Theta & Phi are switched, though referenced in correct order (check Mathworld). Easy to correct, just read "Phi symbol" as Theta & "Theta symbol" as Phi - references & formulas will be in order. This book was written in mid-1970's, guess more? people then used this as convention.
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There are many good free sources on the web for geodesic domes & math plotting through Cartesian x,y,z and/or spherical Theta, Phi coordinates using basic trigonometry. This book cost me $13.57 shipped free brand new & is WELL worth it, even after searching the web...


A final word of caution on building materials for domes in general: if you use wood make sure you take extra fireproofing precautions, unless it's a temporary frame. 2 domes here in town (on same lot) burnt down before fire department got to them - and they were right down the street! The intense heat from both fires left nothing except the slab & melted everything.

So, when they start to burn there is very little time to exit the structure. As energy efficient as they are, the same design allows for a very efficient combustion, especially with wood stud frames & panels. Other problems arise as well with ventilating interior wood frames to help prevent condensation.

There are many other materials that will not burn that could make up the panels (like from American Ingenuity, Inc.), or even a monolithic concrete pour over a temporary plastic covered geodesic wood frame. Another method that doesn't use geodesics is a "monolithic shotcreted airform dome" (from a company called Monolithic Dome Institute).

I have been researching geodesics for a while and have found this book valuable in understanding the subject, however, I would suggest downloading some of the NASA tech briefs about geodesic math (and its free) before spending this amount of money on a book. There are several online sources of info to help the novice.

Well, the time has come for the pirates to take a hike. UC Press is reprinting this book. The information I have indicates both hard and softcover bindings...It will be available this year (2003).

Geodesic Math and How To Use It is an extremely well written book, and with the NASA papers, forms the "canon of applied geodesic math." It is a great book, well written and useful.

To paraphrase Barbara Mandrell, geodesic domes were green when green wasn't cool. I read this book in college and was sorely tempted to steal it out of the university library because it had gone out of print and was just not available new or used anywhere else. I kicked myself later for not yielding to temptation when I went to check it out again and realized that someone else stole it before me! Seriously, give Kenner his rightful due, this is a classic in its field. What is my test for saying so? It has been thirty years since the book's first printing and has yet to see its equal. And there have been many many contenders. I could not recommend any one book higher for hobbyist or even professional reference to geodesic calculation and the practical design of geodesic domes. Though Hugh is no longer with us, five years gone as I am writing this, but the effects of his powerful intellect live on and continue to infect others with his inquisitive spirit by way of such seminal work.

The subject very well presented and in a way that is easy to understand. Gives the underlying math to be able to use our modern computers setting on our desk tops to go far beyond what one person could do 25 years ago.

I don't like to spend money on information that I can get for free. I found plenty of free information about geodesics on the web, but not enough.

I'm glad I spent the cash. This book filled in all the gaps.

It is not for people with weak math skills.

The book seems confusing at first, but if you keep reading and studying you will be rewarded with a deeper understanding of geodesics than you can imagine.

This book is a "must have" for anyone who wants to build their own dome, or just learn more about geodesics.

And yes, it's worth learning the math skills to understand this book.

I was looking for a source of chord lengths for various frequency geodesic domes. This book does this in spades. With all of the variations covered the book may be too involved for what I need. It reads like a textbook and does cover the subject well, from what I've read so far. If you have a question concerning geodesics it will be found in this book. Illustrating is also done well. As a source book it is excellant, if not a bit difficult to read.

I learned a lot more than I needed from this book. It took me two weeks to finish it. At times it made really interesting reading, at other times I just wanted to get it over with. I was interested in the chord factors for modeling. The book was written as a text for future builders. What I desired was the strut chord factors and number of each I would have to create.
I'm still a little confused about the two angles I need to figure out prior to being able to calculate the chord factors. His labeling of struts is different than any I've seen elsewhere. However, they make more sense than the others. With this book you can compare A,B, and C type strut labels to the make sure you are actually using the correct chord factors.

If I ever do build a dome as something other than a model, this will be a handy text.